I've had my car for almost an entire year and I have yet to manage to find a fix for the stalling. For a period of about 2 months there was a point where it didn't stall. It's stalling again and now the idle is extremely low in neutral and when I come to a stop in drive. I've replaced the ignition switch, spark plugs and wire set for them, new distributor cap, new IAC valve (twice), new EGR valve, and new fuel injectors. None of these fixed the stalling issues. I'm at my wits end for this thing. Someone please send help!

 

Make sure the egr isn't getting vacuum at idle (which it shouldn't).

 

How would I go about doing this?

 

I guess 91s have an electric egr valve, so that's not likely your problem.
I'd start by removing the throttle body & cleaning it good. I think they have a gasket set for those.

 

I noticed that the injectors have been replaced, hopefully they aren't re-mans of the OEM Multecs. If so they could still be an issue.

Since this is a 3.1l with an auto there is an idle learn that needs to be done whenever the ECM loses battery power. Good link to that procedure:

https://www.thirdgen.org/forums/v6/1...dle-learn.html

Note that in that link is also information on cleaning the TB. This too is important as the varnish and carbon build up on the blade causes idle issues.

RBob.

 

Also take off the idle air control (IAC) valve and clean all the passages in there too. Check for vacuum leaks and pull the vac line from the fuel pressure regulator and smell for gas. And more detail on those injectors.

 

OK so the injectors are not oem. They are a different brand and definitely better. I've cleaned the entire throttle body and replaced all the gaskets with a direct fit throttle body gasket set I ordered. Idle relearn performed too. Still stalling and a very low idle while coming to a stop in drive and neutral. No vacuum or air leaks either.

 

Double check this. Mine was stalling and the exhaust smelled like fuel. I had gas in this line (there should not be any). I replaced the fuel pressure regulator, and now she runs smooth as silk.

Good Luck

 

The EGR Valves in those year models were prone to sticking open due to carbon getting on the pentel seat. It would usually cause a low or rough idle after the engine was warmed up and it would usually set a code, causing the light to come on. I'd pull the EGR valve and clean the pentel and seat to see if that clears the problem up.

 

The EGR used on this car is different from V8 engines. It's an electric EGR and it has been replaced with a brand new one which did get rid of the EGR SEL code. But it didnt fix the idle.

 

Did you check the ICM?