Need some help - 3B running rich, struggles to stay running

[jbrentd]

Some Background - Car is a '91 CQ with a stock 3B swap. I got the swap running about a month ago and it was idling great, but has progressively gotten worse. I've only run it for short periods. It will fire up, but it struggles to stay running and will die within just a few seconds. Car has been off the road for 3 years. Gas tank was pretty empty and I added 5 gallons of fresh 91 oct.

I've spent the last 3 days working through these things. Items in BOLD are things I found and fixed. Questions I have are in RED text.

1. Tested the IAT sensor (G42). Found one of the connections was bad and repaired it.
2. Removed the ISV to inspect and test. The internals moved freely and it actuated fine when I hit with 12v. I can also hear it when I do an output test.
3. Fresh set of plugs. Previous plugs were new, but fouled up pretty bad.
4. Fuel pump flow test. Measured 500ml in 15sec at 10V. Within the acceptable range, according to my Bentley.
5. Tested O2 wiring. I have a new sensor, but have not tried it yet.
6. Tested coolant temp sensor. Not sure why I didn't test the wiring (see #12 below)
7. Tested MAF sensor and wiring. Here are the back probe voltage readings with the MAF plugged in and just the ignition turned on.
   • pins 1-2 0v
   • pins 1-3 1.42v
   • pins 1-4 0.45v
   • pins 1-5 11.98v
8. Tested coil, even tried a spare coil.
9. Tested G4 sensor and wiring
10. Tested G28 sensor and wiring
11. Checked the flywheel teeth and timing pin
12. Tested the knock sensors and found the plugs were swapped. Fixed that.
13. Started the car and it ran for a bit, pulled codes while running and it came back with a coolant temp sensor open fault. Found one of the pins had come out of the plug. Fixed the coolant temp sensor plug. Car ran well for 15-20 seconds. Fault went away. Then it died again and had problems restarting. Almost like it is getting flooded.
14. Tested the FPR. Held vacuum and 15psi just fine. Is this test sufficient in determining if it working correctly? Or does it only verify the diaphragm is still good?
15. Tested the throttle potentiometer.
    * Voltage across connector pins 1-2 was 4.95v
    * Voltage across connector pins 1-3 was only 3.3v. Bentley says both tests should show 5v. Not sure if that is a big deal. Got the same result from a spare ECU too. What controls that voltage?
    * Resistance across pot pins 1-2 was 2200 ohms
    * Resistance across pot pins 2-3 was 1300 closed and 2920 open. No the 3600 specified in Bentley, but STFA, that seems normal.
16. As I was testing the pot, I noticed the idle micro switch was not making contact with the throttle closed, but I could push it and it would click. So, I adjust the pot so that it makes a contact now.
17. Pulled the distributor cap to inspect the rotor. Dizzy has a brass gear, BTW. Realized that the distributor I am using is the one from my 7A and it has the wide rotor. I have a narrow rotor and a spare 3B distributor and plan to fix this before driving the car, but it should not be a problem at idle while testing my current issue.
18. Verified signal to injectors using a noid light
19. Verified spark
20. Boost leak test. This is probably one of the first things I should have tried, but my tester was setup for a B5 and I had to make a new cap to fit the connection at the MAF. Got one built yesterday and I quickly realized I needed to block off the line going to the PCV, as I was getting positive pressure at the dipstick and it was popping off. I did find and fix a couple small leaks on vacuum lines before running out of time.

Things I need to do:

1. Test the MFTS and wiring. I remembered, as a result of my searching, that the 3B does use the signal from the MFTS in the ECU.
2. Block off the breather system and finish pressure testing the intake plumbing.
3. I wish it would stay running long enough to get some logs for things like the O2 lambda readings and MAF readings.
4. What else is there? I am kind of at a loss at this point. I don't want to start shot-gunning new parts at it.

[newsh]

Thats pretty thorough.

As the engine has not run for a long time I would pull the injectors and have them cleaned and flow tested. Since ethanol arrived in the fuel this seems to be getting more common.

[jbrentd]

Thats pretty thorough.

As the engine has not run for a long time I would pull the injectors and have them cleaned and flow tested. Since ethanol arrived in the fuel this seems to be getting more common.

Thanks for the reply. I'll have to see if there's a place nearby that can service them. You think they can be over supplying fuel? Here's what the plugs looks like before I replaced them. They definitely smelled of fuel.

[igor136]

First of all, you have the wrong spark plugs.

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