Picked up an '88, cranks but won't start...
01-15-2012, 10:59 AM
#31
01-16-2012, 10:14 PM
#32
Three Wheelin'
Join Date: Dec 2002
Location: St Louis, Missouri, USA
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Veleno... No, you probably won't hear the fuel pump run, it only runs when the engine is cranking or running -its a safety thing - just like your 911. The reason to jump straight to fuel pressure is because if it is there, then the DME relay and sensors are good to go and beside it takes like 20 seconds to hook up a fuel gage. All old guys do what is easiest first. Swapping sensors ain't easy. Fuel guages are not only easy but cheap too ($30). Use it once and its paid for. The bouncing tach is sometimes no more than a tiny twitch anyway - not difinative, especially for a newby. While you have the cap off of the rail, what a great time to get that old gas out of the tank and at the same time check the volume delivery of the pump.
Assuming the fuel, pressure and pump is good, its on to the spark - but the spark is not so easy to test (if you've never done it or you don't have a helper). You can buy one of those cheezy spark testers (which is nothing more than a lightbulb and a cable) for like $8 as was suggested by someone who, I'm petty sure, is an "old guy." Those pay for themselves with one use too. If you ever get bit by an ignition system, you'll know why all the old guys have one of those laying in the bottom of their tool box. I just leave the thing connected as the engine will run with it in place, and you get a nice light show too.
On the wiring, My God... surely you're not going to repair wiring based on what some internet guy (like me) tells you? Get a download of Porsche's low quality workshop manual schematics; as bad as they are they are sure a lot more reliable for fixing wires. They are free too. The guy that hacked the wires probably hot-wired them so the fan would run. If the fan isn't located/secured right, it will bang on the edge of the shroud, it might even bind-up and and lead to an overheat. One hack job is often followed by another and another. I'l wager that you curse this guy many times over.
I know this all sounds kinda preachy but I would forget about the damn buzzer and get a peek at the cam and balance belt, and while you're looking roll the crank around and ensure the cam and crank are in time. Just 2 cents from an old guy... Bruce
Any clown can foch-up a car, its always harder to Un-foch one.
Assuming the fuel, pressure and pump is good, its on to the spark - but the spark is not so easy to test (if you've never done it or you don't have a helper). You can buy one of those cheezy spark testers (which is nothing more than a lightbulb and a cable) for like $8 as was suggested by someone who, I'm petty sure, is an "old guy." Those pay for themselves with one use too. If you ever get bit by an ignition system, you'll know why all the old guys have one of those laying in the bottom of their tool box. I just leave the thing connected as the engine will run with it in place, and you get a nice light show too.
On the wiring, My God... surely you're not going to repair wiring based on what some internet guy (like me) tells you? Get a download of Porsche's low quality workshop manual schematics; as bad as they are they are sure a lot more reliable for fixing wires. They are free too. The guy that hacked the wires probably hot-wired them so the fan would run. If the fan isn't located/secured right, it will bang on the edge of the shroud, it might even bind-up and and lead to an overheat. One hack job is often followed by another and another. I'l wager that you curse this guy many times over.
I know this all sounds kinda preachy but I would forget about the damn buzzer and get a peek at the cam and balance belt, and while you're looking roll the crank around and ensure the cam and crank are in time. Just 2 cents from an old guy... Bruce
Any clown can foch-up a car, its always harder to Un-foch one.
01-17-2012, 08:08 AM
#33
Rennlist Member
Thread Starter
Veleno... No, you probably won't hear the fuel pump run, it only runs when the engine is cranking or running -its a safety thing - just like your 911. The reason to jump straight to fuel pressure is because if it is there, then the DME relay and sensors are good to go and beside it takes like 20 seconds to hook up a fuel gage. All old guys do what is easiest first. Swapping sensors ain't easy. Fuel guages are not only easy but cheap too ($30). Use it once and its paid for. The bouncing tach is sometimes no more than a tiny twitch anyway - not difinative, especially for a newby. While you have the cap off of the rail, what a great time to get that old gas out of the tank and at the same time check the volume delivery of the pump.
Assuming the fuel, pressure and pump is good, its on to the spark - but the spark is not so easy to test (if you've never done it or you don't have a helper). You can buy one of those cheezy spark testers (which is nothing more than a lightbulb and a cable) for like $8 as was suggested by someone who, I'm petty sure, is an "old guy." Those pay for themselves with one use too. If you ever get bit by an ignition system, you'll know why all the old guys have one of those laying in the bottom of their tool box. I just leave the thing connected as the engine will run with it in place, and you get a nice light show too.
On the wiring, My God... surely you're not going to repair wiring based on what some internet guy (like me) tells you? Get a download of Porsche's low quality workshop manual schematics; as bad as they are they are sure a lot more reliable for fixing wires. They are free too. The guy that hacked the wires probably hot-wired them so the fan would run. If the fan isn't located/secured right, it will bang on the edge of the shroud, it might even bind-up and and lead to an overheat. One hack job is often followed by another and another. I'l wager that you curse this guy many times over.
I know this all sounds kinda preachy but I would forget about the damn buzzer and get a peek at the cam and balance belt, and while you're looking roll the crank around and ensure the cam and crank are in time. Just 2 cents from an old guy... Bruce
Any clown can foch-up a car, its always harder to Un-foch one.
Assuming the fuel, pressure and pump is good, its on to the spark - but the spark is not so easy to test (if you've never done it or you don't have a helper). You can buy one of those cheezy spark testers (which is nothing more than a lightbulb and a cable) for like $8 as was suggested by someone who, I'm petty sure, is an "old guy." Those pay for themselves with one use too. If you ever get bit by an ignition system, you'll know why all the old guys have one of those laying in the bottom of their tool box. I just leave the thing connected as the engine will run with it in place, and you get a nice light show too.
On the wiring, My God... surely you're not going to repair wiring based on what some internet guy (like me) tells you? Get a download of Porsche's low quality workshop manual schematics; as bad as they are they are sure a lot more reliable for fixing wires. They are free too. The guy that hacked the wires probably hot-wired them so the fan would run. If the fan isn't located/secured right, it will bang on the edge of the shroud, it might even bind-up and and lead to an overheat. One hack job is often followed by another and another. I'l wager that you curse this guy many times over.
I know this all sounds kinda preachy but I would forget about the damn buzzer and get a peek at the cam and balance belt, and while you're looking roll the crank around and ensure the cam and crank are in time. Just 2 cents from an old guy... Bruce
Any clown can foch-up a car, its always harder to Un-foch one.
I admit that I sometimes rely on more knowledgeable members to guide me but I also believe that when a member (new or old) seeks out the collective knowledge of this special group that the advice and suggestions given are with good intentions and never meant to lead anyone in the wrong (just as you have give me above). This is what makes this forum great.
I do have the factory service manuals coming to me so I will double check the wiring. In my inspection of the car I did not notice any other "jimmy rigs" going on but I'll look around again to see if anything looks funny.
The buzzer will forever bug me, as minor as it is!
I tell myself one thing at a time, eventually (soon) I'll get things figured out.
Thanks again to everyone who has continued to offer advice and suggestions
01-17-2012, 06:46 PM
#34
Intermediate
Join Date: Oct 2011
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I ordered the Ignition tune up from lindsey racing, after about a hour installing it she started back up and idled and ran way smoother! I discovered some oil around a spark plug so looks like theres something else im gonna have to fix!
01-29-2012, 12:49 AM
#38
Rennlist Member
Thread Starter
Ok a little update.
I installed some of the new parts (plug wires and dme) and still not starting.
I was trying to replace the speed & reference sensors (since they came in) but damn those things don't want to come off. I tried using an angled tool to get under it and push it up but still no luck, it's really on there tight. Twisting doesn't work either. I'm at a lost trying to get them out.
I'm going to borrow a long pliers and see if I can twist it out with that.
Are there any tips to taking these sensors off? Are they really this hard to remove?
While I was in the area I also found something dangling around there. It's the other end of the service plug/timing sensor used by the dealer. Is it suppose to go somewhere?
I'm waiting on some other parts to come in so I can test spark and fuel as suggested earlier.
I installed some of the new parts (plug wires and dme) and still not starting.
I was trying to replace the speed & reference sensors (since they came in) but damn those things don't want to come off. I tried using an angled tool to get under it and push it up but still no luck, it's really on there tight. Twisting doesn't work either. I'm at a lost trying to get them out.
I'm going to borrow a long pliers and see if I can twist it out with that.
Are there any tips to taking these sensors off? Are they really this hard to remove?
While I was in the area I also found something dangling around there. It's the other end of the service plug/timing sensor used by the dealer. Is it suppose to go somewhere?
I'm waiting on some other parts to come in so I can test spark and fuel as suggested earlier.
01-29-2012, 08:18 PM
#39
Burning Brakes
I wouldn't have tried to remove the CPS crank position sensor personally unless I knew for sure it had failed.
Now it almost definitely doesn't work .
If you replace the DME relay with the 3x way bypass as per Clarkes garage, your fuel pump should run continuously. It should only do this with the bypass in place of the relay.
If the car is using the DME relay as it should then the fuel pump will only run when the engine is cranking or running.
If the fuel pump is not pumping continuously with the 3x way bypass in place then something is wrong.
You should start by checking that you have 12v+ to terminal 30 on the ignition switch and to terminal 30 on the DME relay socket with the ignition off .(the terminals are numbered if you look closely.)
if you have 12v+ at both these terminals then fit the bypass in place of the DME relay. (join terminals 30, 87 & 87b ) The pump should now run continuously even with the ignition switch off.
If it doesn't check fuse 30 (fuel pump fuse ) also thump the fuel pump to see if it starts pumping ?
not pumping ? then check and clean the fuel pump earthing point on the rear valance in the rear hatch area behind the carpet below the number plate light. (brown wires)
Still not pumping ? check that you have 12v+ at the pump . If this doesn't start the fuel pump then it is probably jammed or faulty. You could as a last resort disconect the wiring to the pump and run a 12v+ supply to the pump directly from a 12v battery .
If this doesn't work then you'll need a new pump.
Now it almost definitely doesn't work .
If you replace the DME relay with the 3x way bypass as per Clarkes garage, your fuel pump should run continuously. It should only do this with the bypass in place of the relay.
If the car is using the DME relay as it should then the fuel pump will only run when the engine is cranking or running.
If the fuel pump is not pumping continuously with the 3x way bypass in place then something is wrong.
You should start by checking that you have 12v+ to terminal 30 on the ignition switch and to terminal 30 on the DME relay socket with the ignition off .(the terminals are numbered if you look closely.)
if you have 12v+ at both these terminals then fit the bypass in place of the DME relay. (join terminals 30, 87 & 87b ) The pump should now run continuously even with the ignition switch off.
If it doesn't check fuse 30 (fuel pump fuse ) also thump the fuel pump to see if it starts pumping ?
not pumping ? then check and clean the fuel pump earthing point on the rear valance in the rear hatch area behind the carpet below the number plate light. (brown wires)
Still not pumping ? check that you have 12v+ at the pump . If this doesn't start the fuel pump then it is probably jammed or faulty. You could as a last resort disconect the wiring to the pump and run a 12v+ supply to the pump directly from a 12v battery .
If this doesn't work then you'll need a new pump.
01-30-2012, 02:50 AM
#40
Rennlist Member
Thread Starter
I wouldn't have tried to remove the CPS crank position sensor personally unless I knew for sure it had failed.
Which/where is the CPS? I tried to remove the speed/reference sensors (actually only one) but it would not come loose so it's still on there the same way as before I tried to remove it.
Now it almost definitely doesn't work .
See comment above, it's a different sensor
If you replace the DME relay with the 3x way bypass as per Clarkes garage, your fuel pump should run continuously. It should only do this with the bypass in place of the relay.
Understood. I did try the bypass according the Clark's Garage and the car still didn't start.
If the car is using the DME relay as it should then the fuel pump will only run when the engine is cranking or running.
Understood.
If the fuel pump is not pumping continuously with the 3x way bypass in place then something is wrong.
From Bruce's statement above, I should not be able to hear it even if it's pumping. Are you saying differently?
You should start by checking that you have 12v+ to terminal 30 on the ignition switch and to terminal 30 on the DME relay socket with the ignition off .(the terminals are numbered if you look closely.)
I will check this after I check for spark with the spark tester and fuel pressure.
if you have 12v+ at both these terminals then fit the bypass in place of the DME relay. (join terminals 30, 87 & 87b ) The pump should now run continuously even with the ignition switch off.
If it doesn't check fuse 30 (fuel pump fuse ) also thump the fuel pump to see if it starts pumping ?
I'll check fuse 34 (according to Clark's Garage) to see if it's still working and may replace just to make sure. I might tap the pump too, thanks for the tip.
not pumping ? then check and clean the fuel pump earthing point on the rear valance in the rear hatch area behind the carpet below the number plate light. (brown wires)
Still not pumping ? check that you have 12v+ at the pump . If this doesn't start the fuel pump then it is probably jammed or faulty. You could as a last resort disconect the wiring to the pump and run a 12v+ supply to the pump directly from a 12v battery .
If this doesn't work then you'll need a new pump.
Which/where is the CPS? I tried to remove the speed/reference sensors (actually only one) but it would not come loose so it's still on there the same way as before I tried to remove it.
Now it almost definitely doesn't work .
See comment above, it's a different sensor
If you replace the DME relay with the 3x way bypass as per Clarkes garage, your fuel pump should run continuously. It should only do this with the bypass in place of the relay.
Understood. I did try the bypass according the Clark's Garage and the car still didn't start.
If the car is using the DME relay as it should then the fuel pump will only run when the engine is cranking or running.
Understood.
If the fuel pump is not pumping continuously with the 3x way bypass in place then something is wrong.
From Bruce's statement above, I should not be able to hear it even if it's pumping. Are you saying differently?
You should start by checking that you have 12v+ to terminal 30 on the ignition switch and to terminal 30 on the DME relay socket with the ignition off .(the terminals are numbered if you look closely.)
I will check this after I check for spark with the spark tester and fuel pressure.
if you have 12v+ at both these terminals then fit the bypass in place of the DME relay. (join terminals 30, 87 & 87b ) The pump should now run continuously even with the ignition switch off.
If it doesn't check fuse 30 (fuel pump fuse ) also thump the fuel pump to see if it starts pumping ?
I'll check fuse 34 (according to Clark's Garage) to see if it's still working and may replace just to make sure. I might tap the pump too, thanks for the tip.
not pumping ? then check and clean the fuel pump earthing point on the rear valance in the rear hatch area behind the carpet below the number plate light. (brown wires)
Still not pumping ? check that you have 12v+ at the pump . If this doesn't start the fuel pump then it is probably jammed or faulty. You could as a last resort disconect the wiring to the pump and run a 12v+ supply to the pump directly from a 12v battery .
If this doesn't work then you'll need a new pump.
Thanks for the help and suggestions. I think it's taking me a while to figure this out because shipping takes a while and I only work on the car for a couple of hours!
01-30-2012, 05:32 AM
#41
Burning Brakes
ok veleno thanks for your comprehensive reply.
The CPS is the crank position sensor (same as what you call the speed reference sensor) There is just the one fitted to the transmission on later cars. It tells your ECU exactly where your crankshaft is for TDC and it also tells your CPS the revolutions of the engine.
The CPS is basically a magnet which creates a field that is effected by the teeth on your flywheel. This generates an AC voltage which the ECU uses to produce the correct fuel and ignition spark .
When you used the 3xway bypass did the pump run continuously ? it doesn't matter that the car didn't start. There are loads of issues that could be preventing your car starting other than the DME relay. I just need to check things in a systematic order for it to be diagnostic.
You should definitely hear your pump running using the 3x way bypass. The 3x way bypass is not a DME relay. Bruce was referring to using the DME relay NOT the 3xway bypass. He misunderstood, as you have .
It will be a lot easier if you didn't keep questioning everything and referring to others comments, because you do not understand the Bosch fuel injection and ignition system and it wastes time having to keep explaining a complex system to a lay person . No offence intended.
If you do not check and test the system in a systematic and methodical way I can not help you further. It is completly pointless you checking for fuel and a spark when you don't know what the absence or presense of either tells you.
If you do have not 12v+ on the ignition switch and terminal 30 of the DME relay I can guarantee you will not have fuel or a spark but its pointless me going into pages of explanation trying to teach about the Bosch L jetronic system .
I have a comprehensive understanding of the Bosch fuel injection and ignition system used in our cars. If you trust me and do the checks I suggest in the order that I tell you and answer my questions I can get your car started and running but you must appreciate I'm doing this from 1000's of miles away having never seen your car so you need to be my eyes and ears.
If you would prefer to just try replace and check things randomly at other posters suggestions I'm happy to leave you to it as this will only make the situation worse and frankly my time is too precious to waste
The CPS is the crank position sensor (same as what you call the speed reference sensor) There is just the one fitted to the transmission on later cars. It tells your ECU exactly where your crankshaft is for TDC and it also tells your CPS the revolutions of the engine.
The CPS is basically a magnet which creates a field that is effected by the teeth on your flywheel. This generates an AC voltage which the ECU uses to produce the correct fuel and ignition spark .
When you used the 3xway bypass did the pump run continuously ? it doesn't matter that the car didn't start. There are loads of issues that could be preventing your car starting other than the DME relay. I just need to check things in a systematic order for it to be diagnostic.
You should definitely hear your pump running using the 3x way bypass. The 3x way bypass is not a DME relay. Bruce was referring to using the DME relay NOT the 3xway bypass. He misunderstood, as you have .
It will be a lot easier if you didn't keep questioning everything and referring to others comments, because you do not understand the Bosch fuel injection and ignition system and it wastes time having to keep explaining a complex system to a lay person . No offence intended.
If you do not check and test the system in a systematic and methodical way I can not help you further. It is completly pointless you checking for fuel and a spark when you don't know what the absence or presense of either tells you.
If you do have not 12v+ on the ignition switch and terminal 30 of the DME relay I can guarantee you will not have fuel or a spark but its pointless me going into pages of explanation trying to teach about the Bosch L jetronic system .
I have a comprehensive understanding of the Bosch fuel injection and ignition system used in our cars. If you trust me and do the checks I suggest in the order that I tell you and answer my questions I can get your car started and running but you must appreciate I'm doing this from 1000's of miles away having never seen your car so you need to be my eyes and ears.
If you would prefer to just try replace and check things randomly at other posters suggestions I'm happy to leave you to it as this will only make the situation worse and frankly my time is too precious to waste
02-25-2012, 01:03 AM
#44
Rennlist Member
Thread Starter
I haven't had much time to work on it recently due to travel and other things. I tried the spark tester and no spark so I need to check the coil to see if it's still good. If it is then I'm going to look into bypassing the alarm and looking into the ignition switch as well.
Another thing is that I don't hear the fuel pump running when I use the jumper (and yes there is power at the dme terminal) so I need to look into the fuel pump to see if it's getting power. I'm hoping that next weekend I'll have time to wrench on the car.
If anyone else has suggestions I'm all ears.
Another thing is that I don't hear the fuel pump running when I use the jumper (and yes there is power at the dme terminal) so I need to look into the fuel pump to see if it's getting power. I'm hoping that next weekend I'll have time to wrench on the car.
If anyone else has suggestions I'm all ears.
