1993 945 idling - stalling - running poorly

[cammyers]

Let me say that I appreciate and am aware of all the previous posts that might help me but I'm a bit overwhelmed and I'm hoping someone can help me cut to the chase as the symptoms are so distinctive.

1993 945
NA
Regina injection
Auto trans

Cars starts exactly as it should, runs strong, no misses when revved up. Within 1-3 minutes of idling the car will start to idle poorly, stumble, and stall. Almost as if it is running out of gas. I initially thought or assumed it had and filled tank to halfway but to no avail. Same symptoms. Now what makes this so distinctive, IMO, is that the car will restart perfectly fine as if nothing is wrong and the cycle repeats itself. OBD first reported a TPS code but that was checked and cleaned and then I got an o2 code but now no check engine light as is typical for OBD1 so that just makes things more confusing. Also, I'm not seeing the plug end of the o2 sensor. Is it supposed to be along the firewall on passenger side? I'm not really convinced it is the problem but I'd at least like to unplug it to see if any symptoms change.

- Fuel pump relay seems fine and looks like it was replaced
- have not found any vacuum or intake leaks
- throttle body and tps and connectors have been cleaned
- airbox/filter/air tube all inspected and cleaned
- no voltage issues. Alternator/battery/terminals all good


My next tests are going to be fuel pressure and IAC I guess

All the other potential culprits that I've read about remain:
ECT's - there are 2?
Fuel pump(s) - 2 as well?
Radio suppression relay? Do I have that on this car?
Fire something? What is that?
PCV?
EGR?

What else is there??? It's driving me nuts. Feels like I'm going backwards from what I'm used to diagnosing a modern car even though I'm usually the old head fixing the older cars when my young mechanics can't figure it out but I'm looking bad on this one. Please help!