87 951 VEMS Install
#241
Three Wheelin'
I just got my car back from mechanic after getting head redone. The valve stem seals were gone. I also got new timing gear fitted as teeth in old gear were also badly worn. I also fitted a new ICV. I got car back and idle is oscillating at 1500 rpm. I have loaded original config file Peep supplied the unit with. I have tried adjust the idle ref curve down but it makes no difference. Vacuum lines have been checked and all look good. All I can think is it is ICV. Old one was fine but had new one sitting there, so figured no harm in getting it fitted while doing the work on car. I am thinking I should fit old ICV. What do ppl think ?
Also, make sure that the idle contact switch on the TPS is adjusted properly (this can easily be verified in the VEMS software, it will say IDLE ON at the top of the main screen if the contact is closed). If all of the above are OK, then start playing with the specific idle settings.
#242
Three Wheelin'
Hi Chris
Thanks for replying. It's fixed(see above as I edited my post)
My mechanic sprayed WD40 to check for vacuum leaks and all was good.
After fixing idle issue by deleting the ICV, I just need to reload(again) the original config Peep supplied with the unit and do a decent autotune. The car is running great and I can't wait to get the autotune done.
Bruce
Thanks for replying. It's fixed(see above as I edited my post)
My mechanic sprayed WD40 to check for vacuum leaks and all was good.
After fixing idle issue by deleting the ICV, I just need to reload(again) the original config Peep supplied with the unit and do a decent autotune. The car is running great and I can't wait to get the autotune done.
Bruce
#243
Rennlist Member
Still chasing my start issue where I get a good start and bad start ( lots of stumbling at idle and all rpm ranges.) in Vems which sensor is it getting timing from? The speed or reference sensor? My theory is that I have a bad sensor which is why I would need for it crank over a few times to see TDC and have a "good" or normal start. I've tried numerous settings for cranking, afterstart and warm up. Again issue shows up cold or hot engine. Also DME temp sensor comes to mind also. Car runs great on that good start. But if I get a bad start and try to run it, it feels like I'm running very lean, lots of sputtering and back fire. It almost seems like it's loading a different tuning map, like an A, B setting. Also suspecting fuel system, not enough pressure first few cranks. Or injector settings like latency or dead time. Gonna install an 044 soon. Waiting on the adapter.***did tons of reading and im leaning towards fuel system. Either incorrect injector settings like dwell time/latency, voltage drop to fuel pump, bad check valve or even fuel damper. FPR is good as gauge is steady at idle and reads 3bar/43 psi with vac line off.***
Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?
Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?
Last edited by shortyboy; 10-16-2018 at 03:31 PM.
#244
Three Wheelin'
Still chasing my start issue where I get a good start and bad start ( lots of stumbling at idle and all rpm ranges.) in Vems which sensor is it getting timing from? The speed or reference sensor? My theory is that I have a bad sensor which is why I would need for it crank over a few times to see TDC and have a "good" or normal start. I've tried numerous settings for cranking, afterstart and warm up. Again issue shows up cold or hot engine. Also DME temp sensor comes to mind also. Car runs great on that good start. But if I get a bad start and try to run it, it feels like I'm running very lean, lots of sputtering and back fire. It almost seems like it's loading a different tuning map, like an A, B setting. Also suspecting fuel system, not enough pressure first few cranks. Or injector settings like latency or dead time. Gonna install an 044 soon. Waiting on the adapter.***did tons of reading and im leaning towards fuel system. Either incorrect injector settings like dwell time/latency, voltage drop to fuel pump, bad check valve or even fuel damper. FPR is good as gauge is steady at idle and reads 3bar/43 psi with vac line off.***
Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?
Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?
#245
Rennlist Member
Ive done some short logs as I dont want to run it that long with a bad tune, which it looks like it. It shows lean afr across the board. Also, whenever Im cranking the starter, if rpms on first crank is below 1k, its a bad start, but if it goes past 1k, around 1300rpm it always starts good. But since adjusting injector dead times or latencys, Ive been having good results, car is starting much better and throttle response too. Probably need to adjust it further for cranking at a specific voltage. Still cant find dead times/latency specs for my delphi 55# injectors. Initially VEMS was set to 550cc, where in fact they are 578cc flow rate.
#246
Three Wheelin'
Hi Chris,
Ive done some short logs as I dont want to run it that long with a bad tune, which it looks like it. It shows lean afr across the board. Also, whenever Im cranking the starter, if rpms on first crank is below 1k, its a bad start, but if it goes past 1k, around 1300rpm it always starts good. But since adjusting injector dead times or latencys, Ive been having good results, car is starting much better and throttle response too. Probably need to adjust it further for cranking at a specific voltage. Still cant find dead times/latency specs for my delphi 55# injectors. Initially VEMS was set to 550cc, where in fact they are 578cc flow rate.
Ive done some short logs as I dont want to run it that long with a bad tune, which it looks like it. It shows lean afr across the board. Also, whenever Im cranking the starter, if rpms on first crank is below 1k, its a bad start, but if it goes past 1k, around 1300rpm it always starts good. But since adjusting injector dead times or latencys, Ive been having good results, car is starting much better and throttle response too. Probably need to adjust it further for cranking at a specific voltage. Still cant find dead times/latency specs for my delphi 55# injectors. Initially VEMS was set to 550cc, where in fact they are 578cc flow rate.
Are you saying that you see either 1000 or 1300 RPM while the starter is cranking, before the engine starts? That isn't right, starter speed is ~400 RPM at the best of times. Maybe you are having a version of the trigger errors I keep hearing about? Does the engine RPM reading in VEMS seem to correspond with actual RPM? Hook up a digital timing light to a spark plug wire and compare the readings to what VEMS is showing.
#247
Rennlist Member
I don't see injector latency settings being slightly off as the cause of an intermittent lean running issue. If that were the case, it'd be lean/bad running all of the time. How lean is the AFR when it acts up? If the sputtering/backfiring happens during low speed/low load conditions, I doubt you'll hurt anything.
Are you saying that you see either 1000 or 1300 RPM while the starter is cranking, before the engine starts? That isn't right, starter speed is ~400 RPM at the best of times. Maybe you are having a version of the trigger errors I keep hearing about? Does the engine RPM reading in VEMS seem to correspond with actual RPM? Hook up a digital timing light to a spark plug wire and compare the readings to what VEMS is showing.
Are you saying that you see either 1000 or 1300 RPM while the starter is cranking, before the engine starts? That isn't right, starter speed is ~400 RPM at the best of times. Maybe you are having a version of the trigger errors I keep hearing about? Does the engine RPM reading in VEMS seem to correspond with actual RPM? Hook up a digital timing light to a spark plug wire and compare the readings to what VEMS is showing.
#248
Racer
Thread Starter
Just double checking, but you know the flow rate setting in VEMS is ONLY for if you’re calculating gas mileage, has NO EFFECT on running, only REQ FUEL does. You could put 0 or a million in the Flow Rate box and it will change nothing. Is your req fuel set correctly?
#250
Rennlist Member
#251
Three Wheelin'
Check your throttle position sensor and throttle cable adjustment. Even with all of the glare and blurriness during the tablet screen shots, I can see that the VEMS cannot tell the TPS is seeing idle; if the idle switch circuit is good, the "IAC ON" icon at the top would light up green at idle with the throttle closed all the way. Therefore it is likely that the idle control valve is sometimes playing a role in the engine running, sometimes not, and could even be sticking open.
If I am totally off base and/or you have deleted the idle control valve (or even if not), the culprit is likely an intermittent vacuum leak. Smoke test the entirety of the intake and boost circuits. Check your bypass/recirc/"blowoff" valve. It could be that it is hanging open intermittently and causing a lean condition.
If I am totally off base and/or you have deleted the idle control valve (or even if not), the culprit is likely an intermittent vacuum leak. Smoke test the entirety of the intake and boost circuits. Check your bypass/recirc/"blowoff" valve. It could be that it is hanging open intermittently and causing a lean condition.
#252
Rennlist Member
Check your throttle position sensor and throttle cable adjustment. Even with all of the glare and blurriness during the tablet screen shots, I can see that the VEMS cannot tell the TPS is seeing idle; if the idle switch circuit is good, the "IAC ON" icon at the top would light up green at idle with the throttle closed all the way. Therefore it is likely that the idle control valve is sometimes playing a role in the engine running, sometimes not, and could even be sticking open.
If I am totally off base and/or you have deleted the idle control valve (or even if not), the culprit is likely an intermittent vacuum leak. Smoke test the entirety of the intake and boost circuits. Check your bypass/recirc/"blowoff" valve. It could be that it is hanging open intermittently and causing a lean condition.
If I am totally off base and/or you have deleted the idle control valve (or even if not), the culprit is likely an intermittent vacuum leak. Smoke test the entirety of the intake and boost circuits. Check your bypass/recirc/"blowoff" valve. It could be that it is hanging open intermittently and causing a lean condition.
#253
Three Wheelin'
Still chasing my start issue where I get a good start and bad start ( lots of stumbling at idle and all rpm ranges.) in Vems which sensor is it getting timing from? The speed or reference sensor? My theory is that I have a bad sensor which is why I would need for it crank over a few times to see TDC and have a "good" or normal start. I've tried numerous settings for cranking, afterstart and warm up. Again issue shows up cold or hot engine. Also DME temp sensor comes to mind also. Car runs great on that good start. But if I get a bad start and try to run it, it feels like I'm running very lean, lots of sputtering and back fire. It almost seems like it's loading a different tuning map, like an A, B setting. Also suspecting fuel system, not enough pressure first few cranks. Or injector settings like latency or dead time. Gonna install an 044 soon. Waiting on the adapter.***did tons of reading and im leaning towards fuel system. Either incorrect injector settings like dwell time/latency, voltage drop to fuel pump, bad check valve or even fuel damper. FPR is good as gauge is steady at idle and reads 3bar/43 psi with vac line off.***
Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?
Is anyone running delphi low z 55# injectors? If so, case to share your injector settings?
#254
Drifting
I may be mistaken, but I think Peep told me VEMS doesn't rely on the idle circuit in the standard TPS.
#255
Rennlist Member
I have had same issue since I got VEMS. Usually by second or 3rd start it runs properly. I am wondering if it's either voltage related or maybe sensor gap on speed and ref sensors. Car runs great when it clicks over and is clean. I have 3 br, FPR, 80lb injectors, reasonably new fuel filter, so doubtful it is fuel delivery. I have also removed ICV now, no change, although car idels properly when I get clean start. Nothing I have done has made any difference so have just got used to having to start it a few timees. Very annoying considering how well it runs when its running cleanly