Techmotion

My 93 would stall at low speed, and had a hard time re-starting after the stall. First after having the ECU Capacitors replaced with recommend ones. (thanks LScowboyLS and others from that thread ). That helped overall performance, but still had low speed stall followed by re-start problems. It got bad, would not idle at all. I started working on the Intake and every part that effects idle was cleaned and tested. I Had the IAC valve out and cleaned. Pintle still would not move. So then I cleaned again using strong stuff. First spray and flush out the crap some more .PB Blaster or what have you , let set a few minutes then follow with TB cleaner. Hook up B1 and B2 to battery positive. Use wire or, test light (makes it easier when you can verify that you are grounding the correct terminals). Probe the "S" pins in sequence multiple times (about 25) . Close, then open,then 1/2 close. If you can do all that, chances are you have found the problem. My IAC Valve is now OK. Really, takes at least 20 sequences to step the pintle. I did this while cleaning the TB and tested/setup the throttle position sensor. Also tested/cleaned the Mass Airflow Sensor. Hope this helps

https://docs.google.com/file/d/0B8o6...it?usp=sharing

LScowboyLS

the problem is, most of the time that the IACV has problems, it is a bad bearing and cleaning will do nothing to solve it, the 2 bearings in the IACV must be replaced

Techmotion

Yes, could be the PB Blaster lubed the bearing on the pintle side. Plenty of carbon came out after the PB Blaster soak. I just got finished today. I plan on testing the crap out of this car in the next few weeks. It could also be the TB cleaning, throttle pot calibration, or MAF sensor cleaning (used the MAF special cleaner) that solved the issue. I will post if same problem comes back and I have to replace the IAC or if it something else. So far, 2 test rides and no low speed stalls..

skaterjoes

I seem to have a similar problem. I also thought that my car shutting off with no warning when I came to a stop( no cel, no stuttering) was the ecu. So I had the caps replaced and she ran beautifully for 2 days. Performance was amazing. Shifted beautifully. Pick up was better, even tho she ran great before and best of all, no shut off in drive at a stop or when the ac was on. Unfortunately the shut off happened again today. Before I would just try and crank it in neutral and eventually she would fire up and would drive home. Now it seems to be worse. I had to push her off to the side of the road and when I came back an hour later was able to get her to fire up and drove her home only to have another stall in my driveway when... I came to a stop.

Where is the IAC valve located and did cleaning it work for you?

LScowboyLS

the IAC valve is at the front of the intake, behind the thermostat housing, almost in the center, left to right

in the service manual there are specific tests you can do and this will identify whether the IAC valve's bearing and/or coils are working properly, do you have a copy of the factory service manual?

cleaning can help in some cases, but on our cars, IAC valve bearing failure is far more common than just getting gunked up

Legender

I had the same stalling problem on a 95... few miles on the highway then come to a stop and it would die... would start up fine.. but the idle was just dropping too low as I could see it on the cluster Tach as I approached the stop. I did two things so not sure which one fixed it... did the TB cleaning and replaced the plugs and the wires... the plugs and wires were due at 140k.... and doubt the TB had ever been cleaned. After that work, never had another problem with it. Just sharing my experience.