CIS: Fuel pump relay, and then some...WUR?
10-08-2008, 03:01 AM
#17
Rennlist Member
Check the rear end for heavy fuel smell and or black smoke as it warms. If so, WUR or leaking cold start valve. If not probably vacuum leaks. pressure gauge on WUR inlet line will tell you Very quickly if its behaving or not...
jp 83 Euro S AT 51k...good wur so far
jp 83 Euro S AT 51k...good wur so far
10-08-2008, 04:32 AM
#18
Rennlist Member
Thread Starter
If I had a timing issue, would it run smooth when cold?
The thing is, it does not seem to emit black smoke, the exhaust has the normal look and smell, and no wet stain on the ground under/behind the exhaust tip either. So, from what I can see, exhaust appears normal.
I'm gonna do a thorough visual test for vacuum leaks later today.
Thanks for all your tips guys! I could't maintain (and own) this car without you, seriously!
The thing is, it does not seem to emit black smoke, the exhaust has the normal look and smell, and no wet stain on the ground under/behind the exhaust tip either. So, from what I can see, exhaust appears normal.
I'm gonna do a thorough visual test for vacuum leaks later today.
Thanks for all your tips guys! I could't maintain (and own) this car without you, seriously!
10-08-2008, 08:54 AM
#19
Instructor
If you can get the engine warm, save yourself some time and put a vacuum gauge on the engine. I pull off the brake booster hose and plug the vacuum line into its port in the manifold. With the engine at idle rpm, or even a little faster, if necessary to get it running smoothly, the vac gauge should read 17 inches of mercury (inHg) or more. If it's down around 5, you definitely have a vacuum leak. If it's down a couple of inHg only, you won't have a vacuum leak that is contributing to your problem; so time spent trying to find any leaks won't get you any closer to fixing your problem.
As the other guys have said, you really need to measure the fuel pressures to establish whether your WUR is working or not (or, indeed, whether there is a problem with the fuel distributor).
The rich running when the engine gets warm is consistent with the mixture being adjusted to be rich, so that the engine will start with a failed, or failing, WUR. Someone has to do that physically, however. If the WUR was working a little before, and now has stopped working altogether, you would have had difficulty starting the car, and you'd only have been able to do so if the basic mixture was already set way rich. (BTDT, and my car didn't even sound like starting when the WUR finally did fail altogether. And yes, it goes that quickly; one Friday it was running fine, and the next Monday it wouldn't start.)
Neither a new WUR or a rebuild of the fuel distributor is cheap, so you don't want to do either without knowing what the problem is. If you don't have access to a fuel pressure tester, take the car to a mechanic who works on CIS, even if you only pay him for his time to do the testing and do the repair work yourself.
As the other guys have said, you really need to measure the fuel pressures to establish whether your WUR is working or not (or, indeed, whether there is a problem with the fuel distributor).
The rich running when the engine gets warm is consistent with the mixture being adjusted to be rich, so that the engine will start with a failed, or failing, WUR. Someone has to do that physically, however. If the WUR was working a little before, and now has stopped working altogether, you would have had difficulty starting the car, and you'd only have been able to do so if the basic mixture was already set way rich. (BTDT, and my car didn't even sound like starting when the WUR finally did fail altogether. And yes, it goes that quickly; one Friday it was running fine, and the next Monday it wouldn't start.)
Neither a new WUR or a rebuild of the fuel distributor is cheap, so you don't want to do either without knowing what the problem is. If you don't have access to a fuel pressure tester, take the car to a mechanic who works on CIS, even if you only pay him for his time to do the testing and do the repair work yourself.
back from the lab (garage)
Forget the relay, it works .
It's running rich, I suspect. It runs normally when cold, but as it warms up, things are getting gradually worse. I drove it a couple of miles, and in the end it would idle, but not accelerate. If I ease the throttle on, it wil run smoothly at e.g. 3k rpm. If I hit the throttle agressively, it will cough, hesitate violently, and entertain the neighborhood with loud bangs and flashing from the rear silencer. That spells rich in my book...
It needs to be rich when cold, so that explains the smooth running when cold. But it obviously stays rich as it warms up.
Why?
WUR stuck on, or any other suggestions?
I have a complete spare engine, so I can easily swap parts, but need help to narrow down my options.
Forget the relay, it works .
It's running rich, I suspect. It runs normally when cold, but as it warms up, things are getting gradually worse. I drove it a couple of miles, and in the end it would idle, but not accelerate. If I ease the throttle on, it wil run smoothly at e.g. 3k rpm. If I hit the throttle agressively, it will cough, hesitate violently, and entertain the neighborhood with loud bangs and flashing from the rear silencer. That spells rich in my book...
It needs to be rich when cold, so that explains the smooth running when cold. But it obviously stays rich as it warms up.
Why?
WUR stuck on, or any other suggestions?
I have a complete spare engine, so I can easily swap parts, but need help to narrow down my options.
10-09-2008, 03:56 AM
#20
Rennlist Member
While I was researching my recent issue I ran across this great post by Jay Kempf: http://nichols.nu/tip726.htm It gives a good, quick set of pressure checks that can help you determine if you have a fuel problem and what area it might be in.
10-09-2008, 06:53 AM
#21
Burning Brakes
check, clean and recrimp the multi pin connector by the positive jump stud at the passenger front fender wall if there is a poor connection in the ignition power supply pin or the ground wire it will give you the symptoms you are describing it took me over to 2 yrs to find the prob with mine i changed all the fuel and ignition parts before i found the problem and all it was was a relaxed and dirty pin connector good luck
paul with 4 79 982s and one 77 924
paul with 4 79 982s and one 77 924
10-09-2008, 09:28 AM
#22
While I was researching my recent issue I ran across this great post by Jay Kempf: http://nichols.nu/tip726.htm It gives a good, quick set of pressure checks that can help you determine if you have a fuel problem and what area it might be in.
Dennis
10-09-2008, 07:24 PM
#24
Rennlist Member
My first issue with a WUR pressure going high (and fuelling going badly lean) was caused by a gauze filter blocked by accumulated crud....Read the troublehsooting section in Watson's Bosch Fuel Injection book - makes locating the blockages easy and systematic.
jp 83 Euro S AT 51k
jp 83 Euro S AT 51k
10-11-2008, 02:42 AM
#26
Rennlist Member
The euro distributor may have a different advance curve, suitable for use without EGR.
Someone who knows more about the system may jump in and correct me -- this is based on how EGR is usually implemented.
10-18-2008, 08:54 AM
#27
Rennlist Member
Thread Starter
I just found a few minutes to look at the car this morning...
Who voted for ignition?
It turned out the high voltage lead from the coil to the distributor had come loose at the distributor cap.
When i spotted this, I instantly pushed it back on, and the car died. And has been dead since.
This is somewhat embarrassing, but I don't really know how the ignition circuitry works. Are there fuses in there? What are the giant fuse looking things mounted on the inner fender just ahead of the distributor? What does the box that feeds the green wire do?
I reag 2,2V over the wires to the distributor, but that could be the inductance messing with my instrument, or?
Please enlighten me....
mm
Who voted for ignition?
It turned out the high voltage lead from the coil to the distributor had come loose at the distributor cap. When i spotted this, I instantly pushed it back on, and the car died. And has been dead since.
This is somewhat embarrassing, but I don't really know how the ignition circuitry works. Are there fuses in there? What are the giant fuse looking things mounted on the inner fender just ahead of the distributor? What does the box that feeds the green wire do?
I reag 2,2V over the wires to the distributor, but that could be the inductance messing with my instrument, or?
Please enlighten me....
mm
10-18-2008, 10:04 AM
#28
Those fuse looking things are the resistors I mentioned in post 2 and they should be providing at least 3+volts with the ignition on and more during cranking. Remove the wires and clean the connections. If that doesn't increase the voltage, clean your wires at the jump post and at the starter.
Dennis
Dennis
10-18-2008, 11:01 AM
#29
Rennlist Member
Thread Starter
I did clean up at the resistors, and will do as you suggested at the other points.
But my car instantly changed from running rough to stone dead forever (quoting Motorhead) when I pushed the coil lead on while running. I must have fried something. The coil or the tsz-brain perhaps? Any other suggestions? A somewhat low voltage is not the most urgent issue.... I killed it!!!
But my car instantly changed from running rough to stone dead forever (quoting Motorhead) when I pushed the coil lead on while running. I must have fried something. The coil or the tsz-brain perhaps? Any other suggestions? A somewhat low voltage is not the most urgent issue.... I killed it!!!