A slight miss at idle only.....reason?
08-14-2018, 03:04 AM
#61
Rennlist Member
Thread Starter
I just did another test... one i was being a little lazy to do. jacked up both sides of the car and started it up. laid under the car to hear the distinct sound of the misfire! its definitely on the passenger side and very loud coming out of the #3 cylinder. using a stethoscope i was able to narrow it down. so , now its narrowed down. to further test, i also checked the audible clicking of each injector with the pin-stethascope. the #3 was noticeably quieter. than the others (all other 7).. so, i did a resistance check with a fluke meter... all the injectors were 15.4 ohms, while the #3 injector was 15.7. dont know if that is enough to limit enough current to make a weaker opening or weaker flow, but its interesting that it was the odd ball vs all the others. Temped to buy just one injector, in case this cant be fixed by a flow adjustment, or whatever the do when the match flow them...... seems like the problem is being narrowed down.
08-14-2018, 10:34 AM
#62
Team Owner
maybe you have a vacuum leak at the O ring take the injector out and put some DC111 on the O ring and put it back in be generous,'
not sure of what kind of intake your running either
Also do a leak down for that cylinder
not sure of what kind of intake your running either
Also do a leak down for that cylinder
Last edited by Mrmerlin; 08-14-2018 at 10:57 AM.
08-14-2018, 01:02 PM
#64
Rennlist Member
Thread Starter
since i was able to listen to the exact exhaust runner that was showing the miss, i doubt i need to have injectors all flow tested, especially with the indication that one injector has a weak "clicking" sound when operating vs the others. a better way to spend $60 might be to replace that injector , because if it is bad, flow balancing or cleaning it wont fix the issue. (i dont think)
08-14-2018, 01:25 PM
#65
Rennlist Member
Mark:
The injectors are Bosch 0-280-150-945, also sold as Ford # M9593-B302 or F1SE-E5A and well understood (same as I have in our 6L GT motor). Mark Anderson pointed you to Five-O's web page (red-top, not white), those are good guys. Those injectors are also available on eBay (used/cleaned) for a similar price. Certainly buying one spare to try in that one position would be the absolute minimum sensible thing to do.
The latency (opening-time) for those injectors is NOT the same as stock, so yes there is a high likelihood that by adjusting your fuel-pressure for the proper AFR at WOT, it will be lean at idle. The stock injectors have a 0.93ms latency (Sharktuner's "opening-time" parameter), while the B302's are 1.20ms -- quite a bit slower. This means the actual fuel-squirting time will be LESS than the LH expects. At WOT-- with long injection pulses-- this is a very small difference and one you already accounted for by diddling the fuel pressure. At idle however, with only a 2ms injector pulse, there will be less fuel then the stock LH intended.
Changing the LH latency (opening-time) parameter for different injectors is trivial with Sharktuner of course, as is changing the injector size. But I understand the theological limitations here.
All that aside, the fact that only one injector is causing what sounds like a lean-misfire means that one injector is either slower than the rest, or flowing less fuel. The difference in sound is significant, the higher resistance might be. What you don't know is whether than leanness extends into WOT. If it is just a little slow then maybe not, because the pulses get much longer. BUT if the problem is a lower flow rate then yes, it will also be lean at WOT. THAT would be a problem-- lean-mixture detonation would be brutal-- and you DON'T KNOW.
TWO OPTIONS that I see:
1) The simplest would be to buy some spare injectors and send them all to Witchhunter or elsewhere and get them cleaned and flowtested. Pick the eight that are the closest matched and use those, and save the others as spares or put them back on eBay. (Note that a flow-test will NOT identify a "slow" injector, they are flow-tested wide open).
2) Alternately, get a Sharktuner, set the opening-time and injector size appropriately, adjust fuel-pressure to stock, and do some testing to find out if that one cylinder is getting retarded earlier than others. If it is lean, then it will try to knock earlier as you push the timing.
If this were my engine I would do both. (Oh wait, I did...).
Louie did fit EGT sensors to each exhaust port on his 6.5L build, not simple or cheap. And Todd, if I recall correctly, fit eight WBo2 sensors, one to each exhaust port, but again neither simple nor cheap. This really only makes sense if the injectors can be separately trimmed, which the LH cannot do.
The injectors are Bosch 0-280-150-945, also sold as Ford # M9593-B302 or F1SE-E5A and well understood (same as I have in our 6L GT motor). Mark Anderson pointed you to Five-O's web page (red-top, not white), those are good guys. Those injectors are also available on eBay (used/cleaned) for a similar price. Certainly buying one spare to try in that one position would be the absolute minimum sensible thing to do.
The latency (opening-time) for those injectors is NOT the same as stock, so yes there is a high likelihood that by adjusting your fuel-pressure for the proper AFR at WOT, it will be lean at idle. The stock injectors have a 0.93ms latency (Sharktuner's "opening-time" parameter), while the B302's are 1.20ms -- quite a bit slower. This means the actual fuel-squirting time will be LESS than the LH expects. At WOT-- with long injection pulses-- this is a very small difference and one you already accounted for by diddling the fuel pressure. At idle however, with only a 2ms injector pulse, there will be less fuel then the stock LH intended.
Changing the LH latency (opening-time) parameter for different injectors is trivial with Sharktuner of course, as is changing the injector size. But I understand the theological limitations here.
All that aside, the fact that only one injector is causing what sounds like a lean-misfire means that one injector is either slower than the rest, or flowing less fuel. The difference in sound is significant, the higher resistance might be. What you don't know is whether than leanness extends into WOT. If it is just a little slow then maybe not, because the pulses get much longer. BUT if the problem is a lower flow rate then yes, it will also be lean at WOT. THAT would be a problem-- lean-mixture detonation would be brutal-- and you DON'T KNOW.
TWO OPTIONS that I see:
1) The simplest would be to buy some spare injectors and send them all to Witchhunter or elsewhere and get them cleaned and flowtested. Pick the eight that are the closest matched and use those, and save the others as spares or put them back on eBay. (Note that a flow-test will NOT identify a "slow" injector, they are flow-tested wide open).
2) Alternately, get a Sharktuner, set the opening-time and injector size appropriately, adjust fuel-pressure to stock, and do some testing to find out if that one cylinder is getting retarded earlier than others. If it is lean, then it will try to knock earlier as you push the timing.
If this were my engine I would do both. (Oh wait, I did...).
Louie did fit EGT sensors to each exhaust port on his 6.5L build, not simple or cheap. And Todd, if I recall correctly, fit eight WBo2 sensors, one to each exhaust port, but again neither simple nor cheap. This really only makes sense if the injectors can be separately trimmed, which the LH cannot do.
08-14-2018, 02:49 PM
#66
Rennlist Member
Thread Starter
Hi Jim,
thanks for all the information in your post. good stuff! yes, this is my line of thinking, but i didnt realize the latency issues of the stock vs the 30lbers. as you say, it might not be an issue as i suspect , at WOT, because the duration is so much longer, it might not effect mixture, but at idle ,certainly there is less time for the opening and it could cause a lean miss if the injector is already having some issues . the fact that the one injector feels(sounds) so much weaker than all the rest and its following the misfire cylinder shows that its likely it is the cause. SO, I'll buy a spare 30lber and replace the injector. this sounds like the easiest and most straight forward step. your steps would send all injectors. for which all dont seem to be an issue, just one, to get flowed and if the problem that we suspect that an injector is flowing in a restricted way at IDLE, was the problem, then this step wont detect it as it only balances flow at full opening levels and doesnt address latency. Second, shark tuning is not possible, as my ECU lacks the proper connections, as Bill and i found. however, we were able to do some basic tests to show lack of knocks and mixtures levels.
sure, we could weld in bungs to all exhausts and measure EGTs or 02 sensor readings and find the cylinder that is missing, but i think thats a much more expensive and complicated method to find out something we might (and i emphasis "Might") already know. (that #3 is weak based on the sound of the injector during idle). one of the things we have also seen, is that the plugs, which are a great indicator of how an engine is running, shows normal and nothing different vs other plugs. my unique ability to test the engine over 2hours of WOT levels, immediately having the plugs pulled and read, show no issues of leanness. also clear audio of the exhaust, indicates the miss is only happening at idle or part throttle levels.
your ideas show that it makes sense how an injector can run poorly at idle, because of latency or partially opening, vs WOT, where latency is not an issue because of the small effect it would have on longer duration opening periods of the injector.
so, ill order one right now and put it in and see what it does. Ill do a leak down on that cylinder first , just in case.
thanks again Jim!
Mk
EDIT: just thought of another test. upon start up , where there is no miss, i might check the sound of the injector to see if is sounds differently , after all, the injector plus is probably even longer because there is more fuel during start up cold... the other test , was to try and find to temporarily, increase richness at idle to see if i can replicate the "fix". however, this would only confirm what we already know, that the miss cylinder is fuel related.
JUST ORDERED THE INJECTOR. Thanks Mark!
thanks for all the information in your post. good stuff! yes, this is my line of thinking, but i didnt realize the latency issues of the stock vs the 30lbers. as you say, it might not be an issue as i suspect , at WOT, because the duration is so much longer, it might not effect mixture, but at idle ,certainly there is less time for the opening and it could cause a lean miss if the injector is already having some issues . the fact that the one injector feels(sounds) so much weaker than all the rest and its following the misfire cylinder shows that its likely it is the cause. SO, I'll buy a spare 30lber and replace the injector. this sounds like the easiest and most straight forward step. your steps would send all injectors. for which all dont seem to be an issue, just one, to get flowed and if the problem that we suspect that an injector is flowing in a restricted way at IDLE, was the problem, then this step wont detect it as it only balances flow at full opening levels and doesnt address latency. Second, shark tuning is not possible, as my ECU lacks the proper connections, as Bill and i found. however, we were able to do some basic tests to show lack of knocks and mixtures levels.
sure, we could weld in bungs to all exhausts and measure EGTs or 02 sensor readings and find the cylinder that is missing, but i think thats a much more expensive and complicated method to find out something we might (and i emphasis "Might") already know. (that #3 is weak based on the sound of the injector during idle). one of the things we have also seen, is that the plugs, which are a great indicator of how an engine is running, shows normal and nothing different vs other plugs. my unique ability to test the engine over 2hours of WOT levels, immediately having the plugs pulled and read, show no issues of leanness. also clear audio of the exhaust, indicates the miss is only happening at idle or part throttle levels.
your ideas show that it makes sense how an injector can run poorly at idle, because of latency or partially opening, vs WOT, where latency is not an issue because of the small effect it would have on longer duration opening periods of the injector.
so, ill order one right now and put it in and see what it does. Ill do a leak down on that cylinder first , just in case.
thanks again Jim!
Mk
EDIT: just thought of another test. upon start up , where there is no miss, i might check the sound of the injector to see if is sounds differently , after all, the injector plus is probably even longer because there is more fuel during start up cold... the other test , was to try and find to temporarily, increase richness at idle to see if i can replicate the "fix". however, this would only confirm what we already know, that the miss cylinder is fuel related.
JUST ORDERED THE INJECTOR. Thanks Mark!
Mark:
The injectors are Bosch 0-280-150-945, also sold as Ford # M9593-B302 or F1SE-E5A and well understood (same as I have in our 6L GT motor). Mark Anderson pointed you to Five-O's web page (red-top, not white), those are good guys. Those injectors are also available on eBay (used/cleaned) for a similar price. Certainly buying one spare to try in that one position would be the absolute minimum sensible thing to do.
The latency (opening-time) for those injectors is NOT the same as stock, so yes there is a high likelihood that by adjusting your fuel-pressure for the proper AFR at WOT, it will be lean at idle. The stock injectors have a 0.93ms latency (Sharktuner's "opening-time" parameter), while the B302's are 1.20ms -- quite a bit slower. This means the actual fuel-squirting time will be LESS than the LH expects. At WOT-- with long injection pulses-- this is a very small difference and one you already accounted for by diddling the fuel pressure. At idle however, with only a 2ms injector pulse, there will be less fuel then the stock LH intended.
Changing the LH latency (opening-time) parameter for different injectors is trivial with Sharktuner of course, as is changing the injector size. But I understand the theological limitations here.
All that aside, the fact that only one injector is causing what sounds like a lean-misfire means that one injector is either slower than the rest, or flowing less fuel. The difference in sound is significant, the higher resistance might be. What you don't know is whether than leanness extends into WOT. If it is just a little slow then maybe not, because the pulses get much longer. BUT if the problem is a lower flow rate then yes, it will also be lean at WOT. THAT would be a problem-- lean-mixture detonation would be brutal-- and you DON'T KNOW.
TWO OPTIONS that I see:
1) The simplest would be to buy some spare injectors and send them all to Witchhunter or elsewhere and get them cleaned and flowtested. Pick the eight that are the closest matched and use those, and save the others as spares or put them back on eBay. (Note that a flow-test will NOT identify a "slow" injector, they are flow-tested wide open).
2) Alternately, get a Sharktuner, set the opening-time and injector size appropriately, adjust fuel-pressure to stock, and do some testing to find out if that one cylinder is getting retarded earlier than others. If it is lean, then it will try to knock earlier as you push the timing.
If this were my engine I would do both. (Oh wait, I did...).
Louie did fit EGT sensors to each exhaust port on his 6.5L build, not simple or cheap. And Todd, if I recall correctly, fit eight WBo2 sensors, one to each exhaust port, but again neither simple nor cheap. This really only makes sense if the injectors can be separately trimmed, which the LH cannot do.
The injectors are Bosch 0-280-150-945, also sold as Ford # M9593-B302 or F1SE-E5A and well understood (same as I have in our 6L GT motor). Mark Anderson pointed you to Five-O's web page (red-top, not white), those are good guys. Those injectors are also available on eBay (used/cleaned) for a similar price. Certainly buying one spare to try in that one position would be the absolute minimum sensible thing to do.
The latency (opening-time) for those injectors is NOT the same as stock, so yes there is a high likelihood that by adjusting your fuel-pressure for the proper AFR at WOT, it will be lean at idle. The stock injectors have a 0.93ms latency (Sharktuner's "opening-time" parameter), while the B302's are 1.20ms -- quite a bit slower. This means the actual fuel-squirting time will be LESS than the LH expects. At WOT-- with long injection pulses-- this is a very small difference and one you already accounted for by diddling the fuel pressure. At idle however, with only a 2ms injector pulse, there will be less fuel then the stock LH intended.
Changing the LH latency (opening-time) parameter for different injectors is trivial with Sharktuner of course, as is changing the injector size. But I understand the theological limitations here.
All that aside, the fact that only one injector is causing what sounds like a lean-misfire means that one injector is either slower than the rest, or flowing less fuel. The difference in sound is significant, the higher resistance might be. What you don't know is whether than leanness extends into WOT. If it is just a little slow then maybe not, because the pulses get much longer. BUT if the problem is a lower flow rate then yes, it will also be lean at WOT. THAT would be a problem-- lean-mixture detonation would be brutal-- and you DON'T KNOW.
TWO OPTIONS that I see:
1) The simplest would be to buy some spare injectors and send them all to Witchhunter or elsewhere and get them cleaned and flowtested. Pick the eight that are the closest matched and use those, and save the others as spares or put them back on eBay. (Note that a flow-test will NOT identify a "slow" injector, they are flow-tested wide open).
2) Alternately, get a Sharktuner, set the opening-time and injector size appropriately, adjust fuel-pressure to stock, and do some testing to find out if that one cylinder is getting retarded earlier than others. If it is lean, then it will try to knock earlier as you push the timing.
If this were my engine I would do both. (Oh wait, I did...).
Louie did fit EGT sensors to each exhaust port on his 6.5L build, not simple or cheap. And Todd, if I recall correctly, fit eight WBo2 sensors, one to each exhaust port, but again neither simple nor cheap. This really only makes sense if the injectors can be separately trimmed, which the LH cannot do.
Last edited by mark kibort; 08-14-2018 at 03:26 PM.
08-14-2018, 03:51 PM
#67
Team Owner
do a search on Ebay you can buy a whole set of 8 ready to plug and play for 170.00
Thanks Jim link removed.
Mark is smart enough to find his own injectors
Thanks Jim link removed.
Mark is smart enough to find his own injectors
Last edited by Mrmerlin; 08-14-2018 at 06:49 PM.
08-14-2018, 06:39 PM
#69
Chronic Tool Dropper
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Mark --
Use your IR temp gun to read exhaust port temps. Colder = misfire. Not quite as definitive as having 8 EGT's but it's close. Weld-on thermocouples would probably cost more than the new-injectors solution and for sure would take valuable time.
Use your IR temp gun to read exhaust port temps. Colder = misfire. Not quite as definitive as having 8 EGT's but it's close. Weld-on thermocouples would probably cost more than the new-injectors solution and for sure would take valuable time.
08-14-2018, 06:52 PM
#70
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Thread Starter
08-14-2018, 08:09 PM
#71
Chronic Tool Dropper
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Mark --
The effects of either no spark or no fuel on the same cylinder will be the same. Plug wire is easier, but demands that you ground the plug end of the wire before starting rather than pulling the wire while the engine is already running. Or risk damage to the coil and the spark amplifier. If you have the injection rail covers off, it's easy to pop an individual injector connection to help ID a weak cylinder. Know that the idle stabilizer fights you when you try to find an idle-speed reduction with a dropped cylinder however you do it. Use a throttle-stop to hold the throttle open enough to release the TPS idle contact. Then use a tachometer (NOT the one in the dash...) to identify which dropped cylinder causes the smallest RPM drop. That will be the bad one. Still doesn't pinpoint the cause though, just ID's the weakest cylinder.
Didn't you do compression testing on all cylinders a page or two back? Unless there's a low-compression cylinder that you want to further diagnose, don't waste time on a real leakdown test. Consider a leakdown test as what you will accept as a partial substitution when you can't do a compression test. After that, the test you did with just air and no flow measurement is plenty for finding what's leaking. If you have a low-compression cylinder, you'll be pulling the head anyway for whatever fix it needs so I'm not sure of the benefit. Maybe knowing in advance that a piston or rings are leaking might help decide if the whole engine is coming out vs. pulling one head for a bent or burned valve, or a head gasket.
With all you've done so far, all arrows point to a sticking or -maybe- a partially-blocked injector. Replace them, or at least pull yours and have them cleaned and tested.
It's a TRAIN...
The effects of either no spark or no fuel on the same cylinder will be the same. Plug wire is easier, but demands that you ground the plug end of the wire before starting rather than pulling the wire while the engine is already running. Or risk damage to the coil and the spark amplifier. If you have the injection rail covers off, it's easy to pop an individual injector connection to help ID a weak cylinder. Know that the idle stabilizer fights you when you try to find an idle-speed reduction with a dropped cylinder however you do it. Use a throttle-stop to hold the throttle open enough to release the TPS idle contact. Then use a tachometer (NOT the one in the dash...) to identify which dropped cylinder causes the smallest RPM drop. That will be the bad one. Still doesn't pinpoint the cause though, just ID's the weakest cylinder.
Didn't you do compression testing on all cylinders a page or two back? Unless there's a low-compression cylinder that you want to further diagnose, don't waste time on a real leakdown test. Consider a leakdown test as what you will accept as a partial substitution when you can't do a compression test. After that, the test you did with just air and no flow measurement is plenty for finding what's leaking. If you have a low-compression cylinder, you'll be pulling the head anyway for whatever fix it needs so I'm not sure of the benefit. Maybe knowing in advance that a piston or rings are leaking might help decide if the whole engine is coming out vs. pulling one head for a bent or burned valve, or a head gasket.
With all you've done so far, all arrows point to a sticking or -maybe- a partially-blocked injector. Replace them, or at least pull yours and have them cleaned and tested.
It's a TRAIN...
08-14-2018, 11:32 PM
#72
Rennlist Member
Thread Starter
Mark --
The effects of either no spark or no fuel on the same cylinder will be the same. Plug wire is easier, but demands that you ground the plug end of the wire before starting rather than pulling the wire while the engine is already running. Or risk damage to the coil and the spark amplifier. If you have the injection rail covers off, it's easy to pop an individual injector connection to help ID a weak cylinder. Know that the idle stabilizer fights you when you try to find an idle-speed reduction with a dropped cylinder however you do it. Use a throttle-stop to hold the throttle open enough to release the TPS idle contact. Then use a tachometer (NOT the one in the dash...) to identify which dropped cylinder causes the smallest RPM drop. That will be the bad one. Still doesn't pinpoint the cause though, just ID's the weakest cylinder.
Didn't you do compression testing on all cylinders a page or two back? Unless there's a low-compression cylinder that you want to further diagnose, don't waste time on a real leakdown test. Consider a leakdown test as what you will accept as a partial substitution when you can't do a compression test. After that, the test you did with just air and no flow measurement is plenty for finding what's leaking. If you have a low-compression cylinder, you'll be pulling the head anyway for whatever fix it needs so I'm not sure of the benefit. Maybe knowing in advance that a piston or rings are leaking might help decide if the whole engine is coming out vs. pulling one head for a bent or burned valve, or a head gasket.
With all you've done so far, all arrows point to a sticking or -maybe- a partially-blocked injector. Replace them, or at least pull yours and have them cleaned and tested.
It's a TRAIN...
The effects of either no spark or no fuel on the same cylinder will be the same. Plug wire is easier, but demands that you ground the plug end of the wire before starting rather than pulling the wire while the engine is already running. Or risk damage to the coil and the spark amplifier. If you have the injection rail covers off, it's easy to pop an individual injector connection to help ID a weak cylinder. Know that the idle stabilizer fights you when you try to find an idle-speed reduction with a dropped cylinder however you do it. Use a throttle-stop to hold the throttle open enough to release the TPS idle contact. Then use a tachometer (NOT the one in the dash...) to identify which dropped cylinder causes the smallest RPM drop. That will be the bad one. Still doesn't pinpoint the cause though, just ID's the weakest cylinder.
Didn't you do compression testing on all cylinders a page or two back? Unless there's a low-compression cylinder that you want to further diagnose, don't waste time on a real leakdown test. Consider a leakdown test as what you will accept as a partial substitution when you can't do a compression test. After that, the test you did with just air and no flow measurement is plenty for finding what's leaking. If you have a low-compression cylinder, you'll be pulling the head anyway for whatever fix it needs so I'm not sure of the benefit. Maybe knowing in advance that a piston or rings are leaking might help decide if the whole engine is coming out vs. pulling one head for a bent or burned valve, or a head gasket.
With all you've done so far, all arrows point to a sticking or -maybe- a partially-blocked injector. Replace them, or at least pull yours and have them cleaned and tested.
It's a TRAIN...
good idea about checking the RPM with idle switch disabled. i have a manual switch for that, so i dont need throttle stop (no idle switch for racing, idles switch only for street and start up)
now your comments of spark of injector being the same is not exactly the case. pull a plug wire, or even ground it , you end up spraying gas in that cylinider and it can accumulate . certainly when you reconnect the plug, you can get a big back fire, which cant be good for anything , right?
now, ive listened to the injectors, the suspect bad cylinder has a weak click, different than any of the other 7 injectors. it makes sens. it's not a train. its one injector (or is that the train?).
Ill do the temp check with IR gun too. the good news is, i know what bank it is FOR SURE.. so we are making progress. new injector should be here tomorrow.... ill do the RPM test because that will be interesting.
thanks,
Mark
08-15-2018, 01:15 AM
#73
Chronic Tool Dropper
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...
now your comments of spark of injector being the same is not exactly the case. pull a plug wire, or even ground it , you end up spraying gas in that cylinider and it can accumulate . certainly when you reconnect the plug, you can get a big back fire, which cant be good for anything , right?
now your comments of spark of injector being the same is not exactly the case. pull a plug wire, or even ground it , you end up spraying gas in that cylinider and it can accumulate . certainly when you reconnect the plug, you can get a big back fire, which cant be good for anything , right?
Your statement reinforces my point about disconnecting an injector plug to detect a weak cylinder. Regardless of what's causing the low power from a cylinder, disconnecting the fuel -or- the ignition will have exactly the same effect on the running RPM. Exactly the same. So how many RPM is dropped when you disable a cylinder? Use your precision diagnostic tachometer, the one with the digital readout. The weak cylinder will have the least effect on running RPM, so long as the ISV is disabled. Else the ISV opens a little more to maintain idle RPMs and there's not much test.
Buying a single injector and hoping it has exactly the same characteristics as the seven used ones still in the engine? Um, not the answer we were looking for. If the new one flows less, put it in a cylinder that has restricted intake flow so the mixture is consistent. Flowing fat? Goes to a high airflow cylinder. Don't know? Mount it in the tailpipe for those James Bond special effects. Put a surplus spark plug behind it to get reliable light-off. And put a set of balanced injectors on the engine.
-------
Racers I know work to eliminate or at least minimize as many loose or wildcard variables as they can. You seem to thrive on keeping as many as you can. A real modern engine management package? That's for sissies. Keeping the 40 year old batch-fired technology? Don't you dare SharkTune it for optimum performance! ASSuming that a composite exhaust sample will perfectly represent individual cylinder outputs? What could possibly go wrong with that?
I looked at plugs after every session. You change them every couple years whether they need it or not. New oil because the crank was out for bearing inspection after every race weekend. Do you change the oil as often as once a season? It still starts, it must still be OK. Practice on last race weekend's tires, then qualify and race on new rubber. You drive on already-used tires that you called slippery at the last race, somehow hoping that they've found a rubber God in their lives and are as new again. You probably don't even use German air in them. I religiously kept detailed logs o everything that was done to the car, every change, and maintained a history of what worked at different tracks and different conditions there. You can't remember when the shocks were last serviced or what the settings were. There's some art to winning, and it sits on top of the science of going fast consistently. I'm not a fast driver. But I damn sure know what it takes to consistently present a car capable of winning.
Why not take every possible action to help towards success? Instead of "let's see how little I can do and still find a race mid-pack!" Do it like you mean it!
08-15-2018, 04:56 AM
#74
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Thread Starter
Now, thanks for the info on pulling plugs. everyone i know, pulls plug wires. i didnt know the risk. certainly wont do that again. hope i didnt do any damage in doing so.
thanks for the test regarding RPM and pulliing an injector vs plug wire ( pulled and grounded properly) ill try it. my point was that its not a good idea to pulll a wire and not the injector too, as you wouldnt want fuel shot into the cylinder to pool up. anyway, ill try that. i have to see if i have something accurate enough to measure RPM though.. Hmmm.
as far as the injector. do you think a new or reman injector is going to be off enough to be an issue? if so, i guess if i get the results im hoping for, ill have to send at least a few out to be balanced flowed. the reason im apprehensive, is i would like to buy a set of 24lbers and up the fuel pressure as i had on the holbert original engine if i end up wanting to match flow all the injectors. so, if you think this is dangerous, maybe ill just run it as it is until i buy a new set. i have a few weeks to decide what to do.
now, as far as maint.. you and i have different methods, but i have had a very consistent car, although i do wait for some things to break rather than be pre-emptive on changing everything that is old. dont mistake my use of used tires as a wish for tires that might work better after they have already been proved to be a little slick. usually, i will use tires that are not perfect and fully expect and can predict what performance i will get out of them. this last weekend at laguna, i had new fronts, but some pretty used rears that did cost some time. (about 1 second or so) but so what. i knew my competition, that extra second or so would have not bought me a place, so why expend the money. some would say, SMART. I know i now have the cash to buy tires for the Runoffs because of that "smart " move. ive been doinig this sport in as many levels as there are and have a decent understanding of the risk/reward/costs of racing. you and i dont agree on everything but things i do that you might see as cutting corners has not hurt me and not influenced my reliability at the track. Yes, i know when the shocks were adjusted last and when they were worked on. when they were assembled 20 years ago! got brand new ones front and rear now, are my laps times any different? I think i have learned to drive around a lot of deficiencies of the car.........\
you have seen the tune i run. . what do you think i would gain by a shark tune. what would that cost? first of all, i cant do it without a new ECU. by the way, have you missed the part where my car, and not those that we hear about racing year after year, has run reliably, and NOT blown up! I just dont see the need and dont have the need or interest /cash to dump into a custom fuel /metering system
now, what were you talking about with your oil changes every season, etc. no,i change oil every 3-4 hours of racing. most would agree this is perfect, and so would my oil analysis.
reality check for you . there is nothing you can do to my car to make it a WINNING " car as you say. nothing. anderson's car wouldnt be a winner in my class and it has 200 more hp. so yes, you pick a range of cars and compete.. when i compete in a race class , like with POC, it becomes a top 3 car and you can count on that. so what ? who really cares. racing is expensive. ive done it for 20 years without missing a season . its getting a little old trying to compete with the technology 30 years newer running on tires worth more than 1/2 the value of my car. so, i still like to race, but dont take as serous as i used to....
so, im going to the national championships. i have replaced most all of the major components and am investing in a new set of Michelins for the race. And still running on that wheel bearing 2 years later that you bet would disintegrate after a weekend. remember the one where i just changed the bearing and not the race! no gurantees Bob, im sure there will be several guys that break that have spent more on the weekend than i have spent in my entire career racing. So when you say i dont understand... think again. I do... watch the race of the only 928 ever to run in the national championships. yes, it will run mid -pack and will have done it for CHEAP! and there is nothing you , I or GOD can do to make it run faster. if you think you are so "good" at running a race car that can win.... please explain to me how it is possible to run faster and say catch the car that will be in front of me, let alone win the race. (hint; you are delusional and uninformed if you do) Thanks for the help, but lets get real about racing the 928!
thanks for the test regarding RPM and pulliing an injector vs plug wire ( pulled and grounded properly) ill try it. my point was that its not a good idea to pulll a wire and not the injector too, as you wouldnt want fuel shot into the cylinder to pool up. anyway, ill try that. i have to see if i have something accurate enough to measure RPM though.. Hmmm.
as far as the injector. do you think a new or reman injector is going to be off enough to be an issue? if so, i guess if i get the results im hoping for, ill have to send at least a few out to be balanced flowed. the reason im apprehensive, is i would like to buy a set of 24lbers and up the fuel pressure as i had on the holbert original engine if i end up wanting to match flow all the injectors. so, if you think this is dangerous, maybe ill just run it as it is until i buy a new set. i have a few weeks to decide what to do.
now, as far as maint.. you and i have different methods, but i have had a very consistent car, although i do wait for some things to break rather than be pre-emptive on changing everything that is old. dont mistake my use of used tires as a wish for tires that might work better after they have already been proved to be a little slick. usually, i will use tires that are not perfect and fully expect and can predict what performance i will get out of them. this last weekend at laguna, i had new fronts, but some pretty used rears that did cost some time. (about 1 second or so) but so what. i knew my competition, that extra second or so would have not bought me a place, so why expend the money. some would say, SMART. I know i now have the cash to buy tires for the Runoffs because of that "smart " move. ive been doinig this sport in as many levels as there are and have a decent understanding of the risk/reward/costs of racing. you and i dont agree on everything but things i do that you might see as cutting corners has not hurt me and not influenced my reliability at the track. Yes, i know when the shocks were adjusted last and when they were worked on. when they were assembled 20 years ago!
got brand new ones front and rear now, are my laps times any different? I think i have learned to drive around a lot of deficiencies of the car.........\you have seen the tune i run. . what do you think i would gain by a shark tune. what would that cost? first of all, i cant do it without a new ECU. by the way, have you missed the part where my car, and not those that we hear about racing year after year, has run reliably, and NOT blown up! I just dont see the need and dont have the need or interest /cash to dump into a custom fuel /metering system
now, what were you talking about with your oil changes every season, etc. no,i change oil every 3-4 hours of racing. most would agree this is perfect, and so would my oil analysis.
reality check for you . there is nothing you can do to my car to make it a WINNING " car as you say. nothing. anderson's car wouldnt be a winner in my class and it has 200 more hp. so yes, you pick a range of cars and compete.. when i compete in a race class , like with POC, it becomes a top 3 car and you can count on that. so what ? who really cares. racing is expensive. ive done it for 20 years without missing a season . its getting a little old trying to compete with the technology 30 years newer running on tires worth more than 1/2 the value of my car. so, i still like to race, but dont take as serous as i used to....
so, im going to the national championships. i have replaced most all of the major components and am investing in a new set of Michelins for the race. And still running on that wheel bearing 2 years later that you bet would disintegrate after a weekend. remember the one where i just changed the bearing and not the race!
no gurantees Bob, im sure there will be several guys that break that have spent more on the weekend than i have spent in my entire career racing. So when you say i dont understand... think again. I do... watch the race of the only 928 ever to run in the national championships. yes, it will run mid -pack and will have done it for CHEAP! and there is nothing you , I or GOD can do to make it run faster. if you think you are so "good" at running a race car that can win.... please explain to me how it is possible to run faster and say catch the car that will be in front of me, let alone win the race. (hint; you are delusional and uninformed if you do) Thanks for the help, but lets get real about racing the 928! So... DO NOT DISCONNECT A PLUG WIRE ON A RUNNING 928 ENGINE. You MUST have a path to ground for the spark, at a peak voltage that's less than the breakdown/flashover voltage for the secondary wiring inside the coil. Further, the untethered high voltage in the secondary risks damage to those amplifiers on the front apron connected to the coil primary. Now 4 reasons (two coils, two amplifiers) to not risk damaging them.
Your statement reinforces my point about disconnecting an injector plug to detect a weak cylinder. Regardless of what's causing the low power from a cylinder, disconnecting the fuel -or- the ignition will have exactly the same effect on the running RPM. Exactly the same. So how many RPM is dropped when you disable a cylinder? Use your precision diagnostic tachometer, the one with the digital readout. The weak cylinder will have the least effect on running RPM, so long as the ISV is disabled. Else the ISV opens a little more to maintain idle RPMs and there's not much test.
Buying a single injector and hoping it has exactly the same characteristics as the seven used ones still in the engine? Um, not the answer we were looking for. If the new one flows less, put it in a cylinder that has restricted intake flow so the mixture is consistent. Flowing fat? Goes to a high airflow cylinder. Don't know? Mount it in the tailpipe for those James Bond special effects. Put a surplus spark plug behind it to get reliable light-off. And put a set of balanced injectors on the engine.
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Racers I know work to eliminate or at least minimize as many loose or wildcard variables as they can. You seem to thrive on keeping as many as you can. A real modern engine management package? That's for sissies. Keeping the 40 year old batch-fired technology? Don't you dare SharkTune it for optimum performance! ASSuming that a composite exhaust sample will perfectly represent individual cylinder outputs? What could possibly go wrong with that?
I looked at plugs after every session. You change them every couple years whether they need it or not. New oil because the crank was out for bearing inspection after every race weekend. Do you change the oil as often as once a season? It still starts, it must still be OK. Practice on last race weekend's tires, then qualify and race on new rubber. You drive on already-used tires that you called slippery at the last race, somehow hoping that they've found a rubber God in their lives and are as new again. You probably don't even use German air in them. I religiously kept detailed logs o everything that was done to the car, every change, and maintained a history of what worked at different tracks and different conditions there. You can't remember when the shocks were last serviced or what the settings were. There's some art to winning, and it sits on top of the science of going fast consistently. I'm not a fast driver. But I damn sure know what it takes to consistently present a car capable of winning.
Why not take every possible action to help towards success? Instead of "let's see how little I can do and still find a race mid-pack!" Do it like you mean it!
Your statement reinforces my point about disconnecting an injector plug to detect a weak cylinder. Regardless of what's causing the low power from a cylinder, disconnecting the fuel -or- the ignition will have exactly the same effect on the running RPM. Exactly the same. So how many RPM is dropped when you disable a cylinder? Use your precision diagnostic tachometer, the one with the digital readout. The weak cylinder will have the least effect on running RPM, so long as the ISV is disabled. Else the ISV opens a little more to maintain idle RPMs and there's not much test.
Buying a single injector and hoping it has exactly the same characteristics as the seven used ones still in the engine? Um, not the answer we were looking for. If the new one flows less, put it in a cylinder that has restricted intake flow so the mixture is consistent. Flowing fat? Goes to a high airflow cylinder. Don't know? Mount it in the tailpipe for those James Bond special effects. Put a surplus spark plug behind it to get reliable light-off. And put a set of balanced injectors on the engine.
-------
Racers I know work to eliminate or at least minimize as many loose or wildcard variables as they can. You seem to thrive on keeping as many as you can. A real modern engine management package? That's for sissies. Keeping the 40 year old batch-fired technology? Don't you dare SharkTune it for optimum performance! ASSuming that a composite exhaust sample will perfectly represent individual cylinder outputs? What could possibly go wrong with that?
I looked at plugs after every session. You change them every couple years whether they need it or not. New oil because the crank was out for bearing inspection after every race weekend. Do you change the oil as often as once a season? It still starts, it must still be OK. Practice on last race weekend's tires, then qualify and race on new rubber. You drive on already-used tires that you called slippery at the last race, somehow hoping that they've found a rubber God in their lives and are as new again. You probably don't even use German air in them. I religiously kept detailed logs o everything that was done to the car, every change, and maintained a history of what worked at different tracks and different conditions there. You can't remember when the shocks were last serviced or what the settings were. There's some art to winning, and it sits on top of the science of going fast consistently. I'm not a fast driver. But I damn sure know what it takes to consistently present a car capable of winning.
Why not take every possible action to help towards success? Instead of "let's see how little I can do and still find a race mid-pack!" Do it like you mean it!
08-15-2018, 02:58 PM
#75
Chronic Tool Dropper
Lifetime Rennlist
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Lifetime Rennlist
Member
I guess "cheap" was never a goal for me while campaigning a car. Of course I/we were sensitive to cost, but at the same time my goals included kicking butt in the class. Not just marginal wins, but running away due to better engineering, reliability and prep. Honestly, as much fun and cheap as the 928 is for you, it would not be my platform choice if only because it will never be competitive in class without building another whole car under its skin. You "race" for the fun of driving around cheap and somewhat fast with racer friends. That's great, if that's your goal. Going to the run-offs and maybe on to the national championship? Is it enough fun being a backmarker, and knowing their only chance of placing near the front is if the leaders all crash out in front of you? Yes, I know that there are F1 teams that will never place better than sixth and yet they race anyway. Again, if your goal is driving around with friends who are racers, that's great for you.
Meanwhile... My criticism is pointed at how many loose ends and cheap-driven decisions seem to dominate your program. Doing a major change (different injector flows) and tuning around it with a random fuel pressure change falls it the category. You can add Sharktuning capability to your car with a bit of used wiring harness that includes a diagnostic port. It's functionally a firmware (chip) change to make them fully programmable. When I had my spare LH rebuilt, it was an easy upgrade from the rebuilder to bring it to late standards to support full diagnostics and tuning. Sharktuning won't solve issues caused by unbalanced injector flow, the real subject of the discussion. You mention buying just one injector and putting it in to try and eliminate the symptom you notice at idle, rather than cleaning and flow and spray-pattern testing the whole set. Sharktuning will help you optimize fuel and spark throughout the load and RPM ranges. You 'tune' very safely rich on your WB, nothing wrong with that so long as it's safe through all situations and conditions. Want to go faster? Porken demonstrated that even with stock intake and exhaust, there's 15%+ more power available from optimized mapping. That's with values safe enough to plug-and-play. Ask Jim & Sue Corenman how much they gained after Sharktuning their mild GT stroker. And that was AFTER it got a good initial tune on the dyno. If you feel that an additional 15%+ horsepower wouldn't help you on the track, we need to open a separate sanity discussion. How much would that cost? A couple $hundred would get you the later harness pieces from Mark A. You'd get to install them. You'd get to pay for dyno time for initial tuning, and get to ride with an old laptop for a while as you gather data, and make adjustments between sessions to fine-tune the driveability part and get power where it would do the most for the way you drive. You'd need to get a later set of ROM's to start with to get the diagnostics.
Meanwhile... My criticism is pointed at how many loose ends and cheap-driven decisions seem to dominate your program. Doing a major change (different injector flows) and tuning around it with a random fuel pressure change falls it the category. You can add Sharktuning capability to your car with a bit of used wiring harness that includes a diagnostic port. It's functionally a firmware (chip) change to make them fully programmable. When I had my spare LH rebuilt, it was an easy upgrade from the rebuilder to bring it to late standards to support full diagnostics and tuning. Sharktuning won't solve issues caused by unbalanced injector flow, the real subject of the discussion. You mention buying just one injector and putting it in to try and eliminate the symptom you notice at idle, rather than cleaning and flow and spray-pattern testing the whole set. Sharktuning will help you optimize fuel and spark throughout the load and RPM ranges. You 'tune' very safely rich on your WB, nothing wrong with that so long as it's safe through all situations and conditions. Want to go faster? Porken demonstrated that even with stock intake and exhaust, there's 15%+ more power available from optimized mapping. That's with values safe enough to plug-and-play. Ask Jim & Sue Corenman how much they gained after Sharktuning their mild GT stroker. And that was AFTER it got a good initial tune on the dyno. If you feel that an additional 15%+ horsepower wouldn't help you on the track, we need to open a separate sanity discussion. How much would that cost? A couple $hundred would get you the later harness pieces from Mark A. You'd get to install them. You'd get to pay for dyno time for initial tuning, and get to ride with an old laptop for a while as you gather data, and make adjustments between sessions to fine-tune the driveability part and get power where it would do the most for the way you drive. You'd need to get a later set of ROM's to start with to get the diagnostics.
