I searched but each time it just pulled up a list of a working fault code reader, but my '94 940 N/A car, that I gasket ported the intake/head/exhaust system, is running super fuel rich, making me think a sensor is keeping a fuel control mechanism stuck open. I tried pulling codes, I don't want to start pulling stuff and replacing ***** nilly, I want to fix what's wrong, not theorize and spend money. BUT... my code reader isn't pulling up a damn thing. No LEDs, I'm putting it in key pos 2 without running, battery has plenty of juice. I depress for the injection system on plug #2 for more than 1 sec. less than 3, and nada, zip, zero.

Could be a list of things causing my issues... I can just multimeter each component, check the Throttle Position Sensor for Ohm sweep, clean it etc.

Clean contacts, check the knock sensor, I "think" the tabs may have broken off inside the knock sensor from the harness lead, but my eyes are so shot I can't tell.

other suspects are Mass Air Flow sensor, possibly the ECU-I hope not, but it's dumping fuel. If I pull the battery leads, and "reset" the ecu it runs good cold, then as it warms up, it get's progressively worse, could be coolant temp sensor in the head at cylinder 2...

The car ran fine before I pulled the head off, and did the headgasket port job, but it did sit for awhile in New England summer, rain, etc. So until then I can lean contacts and pin connectors with CRC, and get any corrosion off, make sure my ECU is getting good ground, I can hardwire the knock sensor if those pins are broken, or just rewire an aftermarket friction housing fit from Napa into the harness. I'd love to fix this w/out pulling the manifold and fuel rail off again... but I'd also love to fix it.

My shattered spine is also limited in what I can stand to do labor wise, especially in the cold. I started this thinking it would be a multi weekend job in spring, then had another "brain lesion" event in June so it sat while I recovered for a few months. Timing is spot on, it's a head mounted dist. and, as I said it ran great, and has at times, run with the same "butt dyno" feel of a stock 960 on an N/A car with a VX cam. So I think I can assume my valves and interior are fine. Also, it bogs down when warm, and I hit the throttle, again... TPS maybe, I'll pull and inspect/clean. After it hits 2,500 rpms it takes off like a rocket ship though. Seems all that gas makes it go fast, but until then it's rough as hell, and eventually will stop idling and die all together if left to sit at a light in "D" so I stop, put in park, then shift it and go...slowly.

Couldn't hurt to redo all the vacuum lines... It's been manhandled and they're old. But if that dang code reader would read some codes it'd be great. Even the 1-1-1 isn't blinking....

Thanks ahead of time. Throttle body was cleaned, as was the MAF sensor. I have spares to swap in for the MAF...

 

does your model have a jumper pin similar to my 850? If so, it may be that the jumper's cable has broken right where it enters the diagnostic box... (as mine did). I simply use a paper clip to connect the two when needed.

 

When you pulled the plugs what did they look like. Are they wet/fouled or are they dry. Also did you replace the cold start sensor . If that is not working correctly it will tell the ECU to enrich en the fuel mixture. Start with the plugs and see what you have and while you are there you might want to do a quick compression check.

 

I don't know why, but I posted after this... I didn't have time to right away, but, 20 mins after posting the original I went back to it, took the fuel rail w/blue/greay Bosch injectors and....a NEW fuel pressure regulator....and that's what it was, the FPR. Had a lot of bad advice from places you wouldn't expect it that if thr F.P.R. was bad, it wouldn't run at all, or run well at certain RPMS and not at others. It was like a turbo after 3,000-4,500 rpms, changed the shift point etc. But yeah, the injectors off the N/A car are stock 19lb/hr fat yellow Bosch, but they all functioned and spray tested fine with a 9v battery and a clips to the solenoid leads.

Now the diagnostics still don't pull anything. But Pos #3 side A yields a solid red L.E.D. the others positions on A/B both nothing on every spot. Cleaned any corrosion etc. Nada. Car runs great now... but If still like to be able to pull up othet codes.

This thing... I must resist the urge to turbo it. The head will go on my 90T/I rocket ship with a stage 3 RSI cam next summer.

 

Those plugs are the kind that are held in place with the clear plastic that rots away and leaves nothing. Probably position two the plug is loose and just didn't make contact.

 

Thanks Man! I'll look into it, see if I can rebuild it and get it working.

 

I had to rebuild mine. it was intermittently working. Just as Firebirdparts said, those clear plastic sleeves were totally rotted. I opened the light grey box attached to the diagnostic box and cleared out all of the rotten pieces. I used shrink tubing and rebuilt the unit. It works fine now.

 

Got plenty of that stuff. Thanks Brother. That is EXACTLY what I'll do.