SC runs only when in START

[blg5035]

To start off with some background, when I bought the car it had a hot start issue. It was resolved by replacing the fuel accumulator and replacing the primary pressure regulator on the fuel distributor. The o-ring on the plunger was non-existent. All was good for about a day and a half.

After setting the system pressure, these were the results of a fuel pressure test

1. Year of engine: 1980
2. US or RoW (Rest of World): RoW, non-lambda
3. WUR model number: Porsche pn .009, with upper vacuum port, no side vacuum port

4. Ambient temperature at time of test (in degrees C): 23 [I think]
5. WUR Resistance (in Ohms): ? I checked this once, but didn't write it down. I can measure it if needed
6. System Pressure (in bars): 5
7. Cold Control Pressure (in bars): 1.55
8. Warm Control Pressure (in bars): 2.5
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): I got distracted and only checked it at 5 min, so the time delta was something less than this.
10. Residual Pressure @ 5 min (in bars): 1.5
11. Residual Pressure @ 15 min (in bars): 1.3
12. Residual Pressure @ 30 min (in bars): 1.5
13. Residual Pressure @ 60 min (in bars): N/A


My alcoholic neighbor hit it while it was parked. Luckily she had to drive over two(!) curbs and hit it square in the passenger door. It could have been much worse. The window still went up and down.



I drove the car over to the body shop without any issues that I noticed. When I picked it up however, there was an issue. It would turn over and fire up, but once the ignition returned to RUN it would sputter out and turn off like it ran out of fuel. The service manager said that while they had it, they had more and more trouble starting it. I didn't know what the issue was so I couldn't argue whether it was their fault. Without much of an idea of what was wrong, I tried a few different relays and a spare ignition switch. I had it towed back to my place.

I've looked through a lot of threads to help with troubleshooting, so I will try and summarize everything I've done. Even if some of the tests are off track I have learned a lot

My first thought was the fuel pump went bad. Makes sense if it was harder and harder to start. I checked the pressures again and they appeared to be OK. I did not write the results of this test down, so I can do it again if need be. One thing I have not checked is the fuel flow rate.

A thought I had was since the engine was just running in START and would "run out of fuel" once I let go of the ignition the engine was running solely on the fuel the CSV injects. My understanding is that the CSV is controlled by the thermo time switch. The pic below (not my car) is the TTS, right? I disconnected the two leads and the same thing happened, so I assumed my hypothesis is false. I have not looked at this further.


I was stumped at this point (and still am ). Next I turned to the fuel pump circuit. I know there is something wrong here because the pump runs with the engine off and the ignition in RUN. It has done this since I bought it. When I am doing a fuel pressure test, I get a pressure reading before I turn on the switch in my 87a-30 jumper. However, when I turn the switch on, the pressure goes slightly higher. I think the reason this is happening is evident in my tests of the circuit. I've previously unwittingly driven the car without the fuel pump relay installed.

Basic test for FP and relay circuitry. This is copied from boyt911sc. "Correct result" is in BLACK. My result is in RED. Electricity is not my strength, so bear with me if I did a test wrong.

1. Remove FP relay. Ignition switch off
87...No Power 0V with one DVOM lead on socket and the other on B-
87a...No Power 0V with one DVOM lead on socket and the other on B-
86...No Power (87a and 86 are bridged) 0V with one DVOM lead on socket and the other on B-. Continuity between 87a and 86
85...No Power (should be grounded) 0V with one DVOM lead on socket and the other on B-. Continuity to B-
30...No Power (has ground contact through coils of FP) 0V with one DVOM lead on socket and the other on B-. Continuity to B-

2. Turn ignition switch ON (not START). Relay NOT installed
87...No Power 10mV with one DVOM lead on socket and the other on B-
87a...has Power 11.8V with one DVOM lead on socket and the other on B-
86...has Power 11.8V with one DVOM lead on socket and the other on B-.
85...No Power (should be grounded) 0.75mV with one DVOM lead on socket and the other on B-. NO continuity to B-. I measured resistance to B- a few times different days. I got 276 ohm and ~80 ohm
30...No Power (has ground contact through coils of FP) 8.5V with one DVOM lead on socket and the other on B-. I am not sure about the continuity, especially since the circuit has power.

3. FP relay installed, ignition switch ON. I can take a pic of how I was measuring the relay pins.
87...No Power 12mV with one DVOM lead on socket and the other on B-
87a...has Power 11.75V with one DVOM lead on socket and the other on B-
86...has Power 11.8V with one DVOM lead on socket and the other on B-.
85...Ground 0.66V with one DVOM lead on socket and the other on B-. NO continuity to B-.
30...No Power (has ground contact through coils of FP) 15mV with one DVOM lead on socket and the other on B-. 65 ohms with B-

Test I: Lift AFS plate to activate FP. Ignition@ON With or without relay installed, I hear injection
Test II: Remove FP relay. Ignition ON. Jumper 87a and 30. I hear a noise under the car with just the keyswitch ON. It gets louder when I turn on the jumper switch.

With the key ON, the relay clicks when I pull it in and out. I've played with the relay to learn about it and make sure it is working. With 85 & 86 energized, the relay switched to 87 and stayed there (via continuity test) until the 85-86 circuit was broken.

With the funny voltage at socket 30 in test 2, I decided to look at the AFS circuit next. I wasn't quite as detailed with writing down the results, but I will try and summarize. My conclusion was there was no issue with the AFS or its wiring.

There was continuity between the two pins on the AFS itself and lost continuity when I lifted the sensor plate. With the AFS plug connected and ignition OFF, there was continuity between 85 and B- and when I lifted the plate, continuity was lost.

Next I looked at other parts of the wiring. I loosened the fuse panel in the trunk and the fuel pump relay wiring did not appear to have been messed with. I pulled the back off the ignition switch and nothing appeared to have been messed with other than two crude splices that I removed and wrapped in electrical tape. All the pins fell out, so that was fun getting them all back in


I think that is everything I looked at .

Another thing I have not looked at yet is the wiring at the fuel pump itself.

I think the key is in the fuel pump relay test results, but I am not sure how to resolve some of the "bad" results I am seeing. I appreciate your input.

[zelrik911]

Hi big

I am trying to sort through the maze of confusing Fuel/Ignition symptoms in my own SC, so I totally feel for you!!!
Here are a few ideas:

the fuel pump circuit. I know there is something wrong here because the pump runs with the engine off and the ignition in RUN. It has done this since I bought it.

As you know this is a safety issue (pump should only briefly run when engine is spinning to start) & then stop if no start. I think this is controlled by the tach and the hidden "speed sensor" black box acting as a tachymetric relay, as in other CIS cars, except in an SC it acts on the fuel pump, supposedly when there is a high rev episode . Maybe a PO fiddled with / bypassed this??? Box has an X across it.
Does your model have this or Lambda instead?

The Thermo switch is ( I think) only for the warm up regulator and auxiliary air valve when cold - it runs through the Yellow wire from the starter. The yellow wire circuit is a supposed weak spot.

Too much fuel could be 'flooding' the motor - casing a hard-to-start situation.
Also, you wont run out of fuel as you feared as surplus fuel goes back to the tank.

Good luck

[mreid]

Ham fisted body shop broke your ignition switch (we all know that when a car is hard to start, you just twist the key harder). The ignition contacts in the switch are not made when you release the key from the start position. You can test it by jumping the switch and then replace the switch.

[930cabman]

You may consider moving or installing several jersey barriers to keep your neighbor at bay

[blg5035]

Originally Posted by zelrik911

Hi big

I am trying to sort through the maze of confusing Fuel/Ignition symptoms in my own SC, so I totally feel for you!!!
Here are a few ideas:

the fuel pump circuit. I know there is something wrong here because the pump runs with the engine off and the ignition in RUN. It has done this since I bought it.

As you know this is a safety issue (pump should only briefly run when engine is spinning to start) & then stop if no start. I think this is controlled by the tach and the hidden "speed sensor" black box acting as a tachymetric relay, as in other CIS cars, except in an SC it acts on the fuel pump, supposedly when there is a high rev episode . Maybe a PO fiddled with / bypassed this??? Box has an X across it.
Does your model have this or Lambda instead?

The Thermo switch is ( I think) only for the warm up regulator and auxiliary air valve when cold - it runs through the Yellow wire from the starter. The yellow wire circuit is a supposed weak spot.

Too much fuel could be 'flooding' the motor - casing a hard-to-start situation.
Also, you wont run out of fuel as you feared as surplus fuel goes back to the tank.

Good luck

The car is non-lambda, so I will check the "speed sensor" out. I recall seeing this in some other threads.

Originally Posted by mreid

Ham fisted body shop broke your ignition switch (we all know that when a car is hard to start, you just twist the key harder). The ignition contacts in the switch are not made when you release the key from the start position. You can test it by jumping the switch and then replace the switch.

Thanks mreid, but I had a few ignition switches that I tried. All gave the same result.

Originally Posted by 930cabman

You may consider moving or installing several jersey barriers to keep your neighbor at bay

haha I know right?! I thought I had it in a safe spot

[ossiblue]

Originally Posted by blg5035

(snip...)

Basic test for FP and relay circuitry. This is copied from boyt911sc. "Correct result" is in BLACK. My result is in RED. Electricity is not my strength, so bear with me if I did a test wrong.

1. Remove FP relay. Ignition switch off
87...No Power 0V with one DVOM lead on socket and the other on B-
87a...No Power 0V with one DVOM lead on socket and the other on B-
86...No Power (87a and 86 are bridged) 0V with one DVOM lead on socket and the other on B-. Continuity between 87a and 86
85...No Power (should be grounded) 0V with one DVOM lead on socket and the other on B-. Continuity to B-
30...No Power (has ground contact through coils of FP) 0V with one DVOM lead on socket and the other on B-. Continuity to B-

2. Turn ignition switch ON (not START). Relay NOT installed
87...No Power 10mV with one DVOM lead on socket and the other on B-
87a...has Power 11.8V with one DVOM lead on socket and the other on B-
86...has Power 11.8V with one DVOM lead on socket and the other on B-.
85...No Power (should be grounded) 0.75mV with one DVOM lead on socket and the other on B-. NO continuity to B-. I measured resistance to B- a few times different days. I got 276 ohm and ~80 ohm
30...No Power (has ground contact through coils of FP) 8.5V with one DVOM lead on socket and the other on B-. I am not sure about the continuity, especially since the circuit has power.

3. FP relay installed, ignition switch ON. I can take a pic of how I was measuring the relay pins.
87...No Power [B] 12mV with one DVOM lead on socket and the other on B-
87a...has Power 11.75V with one DVOM lead on socket and the other on B-
86...has Power 11.8V with one DVOM lead on socket and the other on B-.
85...Ground 0.66V with one DVOM lead on socket and the other on B-. NO continuity to B-.
30...No Power (has ground contact through coils of FP) 15mV with one DVOM lead on socket and the other on B-. 65 ohms with B-

Test I: Lift AFS plate to activate FP. Ignition@ON With or without relay installed, I hear injection
Test II: Remove FP relay. Ignition ON. Jumper 87a and 30. I hear a noise under the car with just the keyswitch ON. It gets louder when I turn on the jumper switch.

With the key ON, the relay clicks when I pull it in and out. I've played with the relay to learn about it and make sure it is working. With 85 & 86 energized, the relay switched to 87 and stayed there (via continuity test) until the 85-86 circuit was broken.

With the funny voltage at socket 30 in test 2, I decided to look at the AFS circuit next. I wasn't quite as detailed with writing down the results, but I will try and summarize. My conclusion was there was no issue with the AFS or its wiring.

There was continuity between the two pins on the AFS itself and lost continuity when I lifted the sensor plate. With the AFS plug connected and ignition OFF, there was continuity between 85 and B- and when I lifted the plate, continuity was lost.

Next I looked at other parts of the wiring. I loosened the fuse panel in the trunk and the fuel pump relay wiring did not appear to have been messed with. I pulled the back off the ignition switch and nothing appeared to have been messed with other than two crude splices that I removed and wrapped in electrical tape. All the pins fell out, so that was fun getting them all back in


I think that is everything I looked at .

Another thing I have not looked at yet is the wiring at the fuel pump itself.

I think the key is in the fuel pump relay test results, but I am not sure how to resolve some of the "bad" results I am seeing. I appreciate your input.

You may have issues in more than one location. Note the bold parts of your tests, above.

Test 2 faults (relay removed)

Terminal 87 at the socket connects to the start position of the ignition switch and should have no power until the switch is moved to "start." You have a voltage reading which point to a problem with the switch (or wiring at the switch) because that is the only possible source of voltage along the yellow wire to terminal 87. 10mv is small, but worth a check.

Terminal 30 at the socket is power feed to the FP, it should have no power ever, with the relay removed. You have a power reading which points to a wiring issue with the pump--either feedback from the ground wire to the pump or the pump circuit wiring is getting fed from another source.

Test I faults

With the relay out, the FP should not run, period, unless you have jumped socket terminals 87a and 30. You stated that your hear the "injectors" with or without the relay installed. FP running when AFS plate lifted, relay installed, is normal, but FP running without the relay--regardless of the plate position--is not. It appears the pump is being powered by a source other than the relay.

Test II fault

As mentioned in test I fault, the pump should never run if there is no jumper between 30 and 87a. The fact that it does confirms the pump is getting power from somewhere besides circuit 30 from the relay. Since the pump gets louder when the jumper is made, indicates that the "unjumpered" source is not full voltage and the (now) jumped source provides the adequate power.

I would begin by thoroughly checking the wiring to the FP. Try disconnecting both wires from the FP itself, and run a temporary ground to the chassis and a temporary power wire directly to the relay socket. Secure the temporary wire to the 30 pin of the relay and insert it in the socket. What happens now?

Did your car ever have an alarm/anti-theft system installed?

[boyt911sc]

Originally Posted by blg5035

To start off with some background, when I bought the car it had a hot start issue. It was resolved by replacing the fuel accumulator and replacing the primary pressure regulator on the fuel distributor. The o-ring on the plunger was non-existent. All was good for about a day and a half.

After setting the system pressure, these were the results of a fuel pressure test

1. Year of engine: 1980
2. US or RoW (Rest of World): RoW, non-lambda
3. WUR model number: Porsche pn .09, with vacuum port

4. Ambient temperature at time of test (in degrees C): 23 [I think]
5. WUR Resistance (in Ohms): ? I checked this once, but didn't write it down. I can measure it if needed
6. System Pressure (in bars): 5
7. Cold Control Pressure (in bars): 1.55
8. Warm Control Pressure (in bars): 2.5
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): I got distracted and only checked it at 5 min, so the time delta was something less than this.
10. Residual Pressure @ 5 min (in bars): 1.5
11. Residual Pressure @ 15 min (in bars): 1.3
12. Residual Pressure @ 30 min (in bars): 1.5
13. Residual Pressure @ 60 min (in bars): N/A


My alcoholic neighbor hit it while it was parked. Luckily she had to drive over two(!) curbs and hit it square in the passenger door. It could have been much worse. The window still went up and down.



I drove the car over to the body shop without any issues that I noticed. When I picked it up however, there was an issue. It would turn over and fire up, but once the ignition returned to RUN it would sputter out and turn off like it ran out of fuel. The service manager said that while they had it, they had more and more trouble starting it. I didn't know what the issue was so I couldn't argue whether it was their fault. Without much of an idea of what was wrong, I tried a few different relays and a spare ignition switch. I had it towed back to my place.

I've looked through a lot of threads to help with troubleshooting, so I will try and summarize everything I've done. Even if some of the tests are off track I have learned a lot

My first thought was the fuel pump went bad. Makes sense if it was harder and harder to start. I checked the pressures again and they appeared to be OK. I did not write the results of this test down, so I can do it again if need be. One thing I have not checked is the fuel flow rate.

A thought I had was since the engine was just running in START and would "run out of fuel" once I let go of the ignition the engine was running solely on the fuel the CSV injects. My understanding is that the CSV is controlled by the thermo time switch. The pic below (not my car) is the TTS, right? I disconnected the two leads and the same thing happened, so I assumed my hypothesis is false. I have not looked at this further.


I was stumped at this point (and still am ). Next I turned to the fuel pump circuit. I know there is something wrong here because the pump runs with the engine off and the ignition in RUN. It has done this since I bought it. When I am doing a fuel pressure test, I get a pressure reading before I turn on the switch in my 87a-30 jumper. However, when I turn the switch on, the pressure goes slightly higher. I think the reason this is happening is evident in my tests of the circuit. I've previously unwittingly driven the car without the fuel pump relay installed.

Basic test for FP and relay circuitry. This is copied from boyt911sc. "Correct result" is in BLACK. My result is in RED. Electricity is not my strength, so bear with me if I did a test wrong.

1. Remove FP relay. Ignition switch off
87...No Power 0V with one DVOM lead on socket and the other on B-
87a...No Power 0V with one DVOM lead on socket and the other on B-
86...No Power (87a and 86 are bridged) 0V with one DVOM lead on socket and the other on B-. Continuity between 87a and 86
85...No Power (should be grounded) 0V with one DVOM lead on socket and the other on B-. Continuity to B-
30...No Power (has ground contact through coils of FP) 0V with one DVOM lead on socket and the other on B-. Continuity to B-

2. Turn ignition switch ON (not START). Relay NOT installed
87...No Power 10mV with one DVOM lead on socket and the other on B-
87a...has Power 11.8V with one DVOM lead on socket and the other on B-
86...has Power 11.8V with one DVOM lead on socket and the other on B-.
85...No Power (should be grounded) 0.75mV with one DVOM lead on socket and the other on B-. NO continuity to B-. I measured resistance to B- a few times different days. I got 276 ohm and ~80 ohm
30...No Power (has ground contact through coils of FP) 8.5V with one DVOM lead on socket and the other on B-. I am not sure about the continuity, especially since the circuit has power.

3. FP relay installed, ignition switch ON. I can take a pic of how I was measuring the relay pins.
87...No Power 12mV with one DVOM lead on socket and the other on B-
87a...has Power 11.75V with one DVOM lead on socket and the other on B-
86...has Power 11.8V with one DVOM lead on socket and the other on B-.
85...Ground 0.66V with one DVOM lead on socket and the other on B-. NO continuity to B-.
30...No Power (has ground contact through coils of FP) 15mV with one DVOM lead on socket and the other on B-. 65 ohms with B-

Test I: Lift AFS plate to activate FP. Ignition@ON With or without relay installed, I hear injection
Test II: Remove FP relay. Ignition ON. Jumper 87a and 30. I hear a noise under the car with just the keyswitch ON. It gets louder when I turn on the jumper switch.

With the key ON, the relay clicks when I pull it in and out. I've played with the relay to learn about it and make sure it is working. With 85 & 86 energized, the relay switched to 87 and stayed there (via continuity test) until the 85-86 circuit was broken.

With the funny voltage at socket 30 in test 2, I decided to look at the AFS circuit next. I wasn't quite as detailed with writing down the results, but I will try and summarize. My conclusion was there was no issue with the AFS or its wiring.

There was continuity between the two pins on the AFS itself and lost continuity when I lifted the sensor plate. With the AFS plug connected and ignition OFF, there was continuity between 85 and B- and when I lifted the plate, continuity was lost.

Next I looked at other parts of the wiring. I loosened the fuse panel in the trunk and the fuel pump relay wiring did not appear to have been messed with. I pulled the back off the ignition switch and nothing appeared to have been messed with other than two crude splices that I removed and wrapped in electrical tape. All the pins fell out, so that was fun getting them all back in


I think that is everything I looked at .

Another thing I have not looked at yet is the wiring at the fuel pump itself.

I think the key is in the fuel pump relay test results, but I am not sure how to resolve some of the "bad" results I am seeing. I appreciate your input.

blg5035,

I have not gone over to the very detail of your test results but I am impressed with your written test results. It reminded me of LJ who writes very detailed and concise sentences. Anyway, my suggestion at this point is to repeat the tests using a test light instead of VoM. For the continuity test use either positive (+) or negative (-) pole/s of the battery for power or ground source respectively.

Install a pressure gauge to determine if the FP is activated or not during the test. What you heard could be or might not be the FP. Same with the fuel injectors. Pull them out and observe. Visual results are more reliable than audio. What you heard could be something else.

Lastly, double check the Bosch ID numbers of the WUR. You said it looks like 09 from your picture. But I see a different number (?). Keep us posted. Thanks.

Tony

[ossiblue]

Anyway, my suggestion at this point is to repeat the tests using a test light instead of VoM. For the continuity test use either positive (+) or negative (-) pole/s of the battery for power or ground source respectively.

Install a pressure gauge to determine if the FP is activated or not during the test. What you heard could be or might not be the FP. Same with the fuel injectors. Pull them out and observe. Visual results are more reliable than audio. What you heard could be something else.

I agree with Tony's post, above. We have only the information you provide so double checking and being certain of your observations is essential--in this case, the sounds you hear which appear to be the FP or the injectors. Electrical tests with a test light will help simplify the diagnoses.

[blg5035]

Thanks for the responses guys. I'm working on your suggestions.

Originally Posted by ossiblue

I would begin by thoroughly checking the wiring to the FP. Try disconnecting both wires from the FP itself, and run a temporary ground to the chassis and a temporary power wire directly to the relay socket. Secure the temporary wire to the 30 pin of the relay and insert it in the socket. What happens now?

Did your car ever have an alarm/anti-theft system installed?

I've got the fuel pump shield off and took a look at the wiring at the pump. Nothing appeared off with the wiring. I will be doing your temporary wire suggestion next. Where would be a good ground point?

I do not know if the car has had an alarm before. When I bought the car a year ago, I was not given a "clicker" (forgot the correct word).

How I found the fuel pump:


Covers off:


Fuel pump part number: I think I see Bosch 0 580 254 984. I have a few other pics that I got the full number from.

Originally Posted by boyt911sc

blg5035,

Lastly, double check the Bosch ID numbers of the WUR. You said it looks like 09 from your picture. But I see a different number (?). Keep us posted. Thanks.

Tony

Should I be looking at A or B? A = 09 & B = 086.?



When I was putting the "pope hat" back on the throttle and AFS, I noticed the vacuum line from the WUR was disconnected. I cannot say when this happened. The line is pretty dry, so I will look at getting a replacement.

Another thing I noticed was there is a pretty sharp bend in the wire bundle going to the FP relay socket. This is when it is going around the fuel filler neck. Maybe some insulation broke and wires are touching? I will get a picture this weekend, although the sheathing is still intact.

[gomezoneill]

You're chasing your tail and over thinking this thing. It ran fine before it was hit therefore something happened at the body shop or the accident caused the problem. Start over and rethink the issue.

[ossiblue]

Originally Posted by gomezoneill

You're chasing your tail and over thinking this thing. It ran fine before it was hit therefore something happened at the body shop or the accident caused the problem. Start over and rethink the issue.

Disagree.

It doesn't matter who or what caused the problem, he has found the problem--at least one of them.

His fuel pump runs without the relay--that is a problem.

He has inadvertently driven the car with the relay removed--that is a problem.

The fuel pump runs with the ignition switch in the "on" position--that is a problem.

The fuel pump runs whether or not the afs is lifted--that is a problem.

The electrical tests at the relay socket indicate power to the pump with no relay installed--that is a problem.

Relay installed, the electrical readings indicate a leaking of current at pins that should have no power, and the pump runs when it shouldn't--that is a problem.

All of the above point to a wiring problem to the pump and that is what he's first trying to address. Once that's taken care of, if a problem persists he will move on to diagnoses. I don't see him chasing his tail by any means.

[boyt911sc]

Originally Posted by ossiblue

Disagree.

It doesn't matter who or what caused the problem, he has found the problem--at least one of them.

His fuel pump runs without the relay--that is a problem.

He has inadvertently driven the car with the relay removed--that is a problem.

The fuel pump runs with the ignition switch in the "on" position--that is a problem.

The fuel pump runs whether or not the afs is lifted--that is a problem.

The electrical tests at the relay socket indicate power to the pump with no relay installed--that is a problem.

Relay installed, the electrical readings indicate a leaking of current at pins that should have no power, and the pump runs when it shouldn't--that is a problem.

All of the above point to a wiring problem to the pump and that is what he's first trying to address. Once that's taken care of, if a problem persists he will move on to diagnoses. I don't see him chasing his tail by any means.

LJ,

I completely agree with your statements. There are people in this forum who think they are knowledgeable in the subject and keep giving advises. Well, we can not prevent them from getting involve in a forum like this. The best we could do is ignore and use prudence who you listen too. The sad fact is that these 'persons' don't realize or feel their lack of technical knowledge about the subject matter and would come back with more BS. Wait and see.

Tony

[gomezoneill]

Originally Posted by boyt911sc

LJ,

I completely agree with your statements. There are people in this forum who think they are knowledgeable in the subject and keep giving advises. Well, we can not prevent them from getting involve in a forum like this. The best we could do is ignore and use prudence who you listen too. The sad fact is that these 'persons' don't realize or feel their lack of technical knowledge about the subject matter and would come back with more BS. Wait and see.

Tony

I'll start this by saying you're well respected on this board and I know you've helped may members but you can be abrasive at times so I want to show you what it's like to be insulted.

Before you insult someone you know nothing about, perhaps you should learn how to construct sentences and spell correctly. So I fixed it for you.

I completely agree with your statements. There are people in this forum who think they are knowledgeable in the subject, and keep giving advice. Well, we cannot prevent them from getting involved in a forum like this. The best we can do is ignore, and use prudence about whose advice you follow. The sad fact is that these people don't realize they are lacking in technical knowledge about the subject and would just come back with more BS. Wait and see.


The "real sad fact" is that I've seen many of your posts where you insult people who you know nothing about. You're judgmental. After all, you don't know everything although you might think you do.

My point to the OP was: he should keep it simple. The problem began after the body shop worked on the car. I would start tracing back from there.

Maybe you shouldn't post here, as you can't spell or put two sentences together correctly. That makes you unreliable. How do you like being insulted? Feel good?

Now I'll wait for your BS.

[blg5035]

Tony/LJ, I'm not sure if you noticed I had made a post #9 with a few answers and questions for you
SC runs only when in START

I'll continue with the tests I did over the weekend. The first one I did was LJ's suggestion below.

I would begin by thoroughly checking the wiring to the FP. Try disconnecting both wires from the FP itself, and run a temporary ground to the chassis and a temporary power wire directly to the relay socket. Secure the temporary wire to the 30 pin of the relay and insert it in the socket. What happens now?

Setup:


First I checked continuity from end to end of the wires and then to the FP itself when the wires were attached. I also checked continuity between the free end of the + wire to the free end of the - wire. I crimped a pin to the end of the red wire and connected it to Pin 30 of FP relay socket. With the yellow wire attached to the - of the FP, I didn't really see what I thought was a chassis ground, so I touched the end of the - wire to B-, and a few places I thought could be a chassis ground. At no point did the FP run. I did this a few times a few different days just in case I did not have the ignition switch ON one time.

This is definitely contrary to what we thought would happen, since my previous tests showed 8V at Pin 30 with the ignition ON.

Next, I removed the temporary wires from the FP. I did the FP relay socket tests twice: 1. Nothing connected to the FP (neither temporary wires nor engine harness)
2. Engine harness connected to the FP
I bought a test light, as suggested, to perform these tests.

No wires connected to FP
1. FP relay removed. Ignition OFF
87: TL on B-, No light
87a: TL on B-, No light
86: TL on B-, No light, Continuity to 87a
85: TL on B-, No light, Continuity to B-
30: TL on B-, No light, Continuity to B-

2. Ignition ON, no relay
87: TL on B-, No light
87a: TL on B-, Light
86: TL on B-, Light
85: TL on B-, No light; TL on B+, Light
30: TL on B-, No light; TL on B+, Light

3. FP relay installed, Ignition ON
87: TL on B-, No light
87a: TL on B-, Light
86: TL on B-, Light
85: TL on B-, No light; TL on B+, Light
30: TL on B-, No light; TL on B+, Light

Two pics of my relay setup for test 3:



FP harness reattached to FP Same results as previous.
1. FP relay removed. Ignition OFF
87: TL on B-, No light
87a: TL on B-, No light
86: TL on B-, No light, Continuity to 87a
85: TL on B-, No light, Continuity to B-
30: TL on B-, No light, Continuity to B-

2. Ignition ON, no relay
87: TL on B-, No light
87a: TL on B-, Light
86: TL on B-, Light
85: TL on B-, No light; TL on B+, Light
30: TL on B-, No light; TL on B+, Light

3. FP relay installed, Ignition ON
87: TL on B-, No light
87a: TL on B-, Light
86: TL on B-, Light
85: TL on B-, No light; TL on B+, Light
30: TL on B-, No light; TL on B+, Light

Picture of the FP harness reattached. I confirmed with a wiring diagram from PP that the black wire goes to the + and the orange goes to the -, which is contrary to the typical black being the ground. From the "Covers Off" picture in post #9, the harness was attached "correctly" before I touched it.


Like the results from the "temporary wire" test, these contrast with my initially posted results that had 8V at pin 30 of the FP relay socket.

During the second test above with the FP harness connected, I noticed I did not hear the fuel pump when I had the ignition ON during steps 2 and 3. This is NOT what was happening before I disconnected the FP harness wires. After the socket tests, I put in my jumper switch between 87a and 30 to make sure I didn't lose my hearing. Turning the jumper switch ON, turned the fuel pump on. I stuck my head under the car to confirm. With the jumper OFF, the fuel pump was quiet. I also reinstalled the FP relay and turned the ignition ON and did not hear the FP.

This was very odd, because I do not know what changed other than me disconnecting and reconnecting the FP wires.

With the FP circuit now seemingly working correctly, I retested fuel pressures. I will note again that the fuel pressures in my first test were taken BEFORE the car was hit. These most recent results, taken today, I believe are showing an issue with the WUR.

1. Year of engine: Chassis is 1980. See ESN
2. US or RoW (Rest of World): VIN indicates RoW and Owner's manual ist auf Deutsch. See ESN


3. WUR model number: In this pic I see 0 438 140 009

4. Ambient temperature at time of test (in degrees C): 31 degC
5. WUR Resistance (in Ohms): 30.7 Ohms, confirmed a few times different days
6. System Pressure (in bars): 4.9
7. Cold Control Pressure (in bars): 5.3
8. Warm Control Pressure (in bars): No change when plug-in WUR harness
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): N/A
10. Residual Pressure @ 5 min (in bars): 1.8
11. Residual Pressure @ 15 min (in bars): 1.1
12. Residual Pressure @ 30 min (in bars): 1.1
13. Residual Pressure @ 60 min (in bars): N/A

Lastly, I tried to start the engine with the pressure gages installed. When cranking and the WUR-side valve OPEN, the fuel pressure was around 5 bar.

What are some diagnostic tests that I can do on the WUR? I'm going to see if my local shop has a spare 009 WUR that I could borrow.

[boyt911sc]

Ben,

Do not waste your valuable time using the WUR-009. First, this is the wrong WUR for your engine. Secondly, WUR-009 is one of the most unpredictable WUR for 911 that I came to work on. Just the other day, I was testing and calibrating a WUR-009 and spent a good 4 hours testing it and trying to get some fuel pressure readings to no avail. What was surprising was it was working the day before. I have six (6) of these WUR-009 and half of them show erratic readings or no readings at all. But had readings before.

When I informed the owner that I was having difficulties getting the WUR-009 to pass the series of tests, and would need more time to evaluate this erratic WUR, he pulled the plug. He wanted it back ASAP and returned to him the following day. So I am sending it back to him ASAP.

My suggestion to you is use the correct WUR period. No if or but. Establish a baseline data for your control fuel pressures versus time. If you could collect the data point (fuel pressure) at 30 sec. intervals instead of per min. would be a better reference.

Tony

[blg5035]

Originally Posted by boyt911sc

Ben,

Do not waste your valuable time using the WUR-009. First, this is the wrong WUR for your engine. Secondly, WUR-009 is one of the most unpredictable WUR for 911 that I came to work on. Just the other day, I was testing and calibrating a WUR-009 and spent a good 4 hours testing it and trying to get some fuel pressure readings to no avail. What was surprising was it was working the day before. I have six (6) of these WUR-009 and half of them show erratic readings or no readings at all. But had readings before.

When I informed the owner that I was having difficulties getting the WUR-009 to pass the series of tests, and would need more time to evaluate this erratic WUR, he pulled the plug. He wanted it back ASAP and returned to him the following day. So I am sending it back to him ASAP.

Tony, what would be the correct WUR? From this table on Jim's Basement Workshop, it appears my -009 WUR was used on 74-75. Would the correct one be -045? How would I go about "trading" my WUR for a different PN? This is new to me.



Pics of my FD pn if that helps. I see 0 438 100 031

My suggestion to you is use the correct WUR period. No if or but. Establish a baseline data for your control fuel pressures versus time. If you could collect the data point (fuel pressure) at 30 sec. intervals instead of per min. would be a better reference.

Tony

I am not sure what you mean here. Do you mean to:
1. Note the residual pressure at 30 second intervals OR
2. Note the warm control pressure at 30 second intervals?

The other tests give instantaneous readings.

If you meant #2, I can't have a time-based baseline since the WUR is not controlling the pressures.

[ossiblue]

I believe Tony means to chart the rise in control pressure in 30 sec. intervals. However, as your post indicates, you have discovered another problem--your system pressure and control pressure are essentially the same. I don't have Tony's experience with testing/calibrating various WURs so his comments about the unreliability of the 009 may account for your problem.

You can run a couple of tests to try and narrow down the pressure issue. What you describe typically points to a blocked WURS or return line from the WUR to the tank. Either disconnect the afs sensor wire in the engine compartment, or remove the relay and jump 30 and 87a to allow the pump to work in the "on" position. Start the pump, open the gas filler cap, and listen for the flow of fuel back into the tank. If you can't hear it, you may have a blocked WUR or return line.

Remove the return line from the WUR. Blow low pressure air through the line and see if you can hear bubbling in the tank. If so, the line is clear but the WUR is still suspect. If no bubbling, the line is blocked and needs to be cleared. Once clear, retest the flow through the WUR.

Whether or not you find the fuel doesn't pass through the WUR, please post your results if you decide to carry out the tests.

[Joe Bob]

Who worked on it last? Have you considered taking it to them?

[boyt911sc]

Ben,

Could you post the number for the engine type (930/xx). Your '80 RoW engine with FD-031 could use either WUR-045 or -069. But before you go buying parts, I would suggest that you check and test the fuel flow in the system. The appearance of the rusted FD is very alarming. Hopefully, the rust is all external and not present in the interior. Secondly, both the FD and WUR should be good and working to minimize your problem getting the motor to run. If you don't have a significant air leak in the system and the fuel pressures are close to spec, you should be able to start and run the engine. So the key for an easy start up is to have these two (2) critical CIS components in good working condition. Whatever you do, refrain from tinkering the mixture setting at this stage if you already did or someone before you has tweaked it, it would be more challenging.

I could lend you a set FD and WUR for you to use and try on your engine. You don't have to buy them. They are just loaners and could save you time and money including aggravation in your troubleshooting. PM me if you are interested. I am two (2) weeks away from a family vacation for several weeks and won't be home in August. Are you doing the work yourself or a shop? Keep us posted.

Tony

[blg5035]

Originally Posted by ossiblue

You can run a couple of tests to try and narrow down the pressure issue. What you describe typically points to a blocked WURS or return line from the WUR to the tank. Either disconnect the afs sensor wire in the engine compartment, or remove the relay and jump 30 and 87a to allow the pump to work in the "on" position. Start the pump, open the gas filler cap, and listen for the flow of fuel back into the tank. If you can't hear it, you may have a blocked WUR or return line.

Remove the return line from the WUR. Blow low pressure air through the line and see if you can hear bubbling in the tank. If so, the line is clear but the WUR is still suspect. If no bubbling, the line is blocked and needs to be cleared. Once clear, retest the flow through the WUR.

Whether or not you find the fuel doesn't pass through the WUR, please post your results if you decide to carry out the tests.

Good suggestion. I'll try this this weekend.

Originally Posted by Joe Bob

Who worked on it last? Have you considered taking it to them?

The last time it was in a shop was last July. I've done some minimal work since then. I replaced the o-ring on the primary pressure regulator to fix a hot start issue.
They key events were the car getting hit and it was at the body shop when it started having issues.

Originally Posted by boyt911sc

Ben,

Could you post the number for the engine type (930/xx). Your '80 RoW engine with FD-031 could use either WUR-045 or -069.

I see 930/09

I could lend you a set FD and WUR for you to use and try on your engine. You don't have to buy them. They are just loaners and could save you time and money including aggravation in your troubleshooting. PM me if you are interested. I am two (2) weeks away from a family vacation for several weeks and won't be home in August. Are you doing the work yourself or a shop? Keep us posted.

Tony

I'm doing the work myself. PM Sent