Weird stalling issue

[tomb]

It revs fine too, I can punch the throttle and there is no stumble at all, idle drops right back where it should. Could that still be IAC?

Sounds like you have good plugs and wires, with it running so smooth indicates that most primary systems are in spec. IE: timing, fuel mixture... Your problem statement should be, "low power at idle" I don't necessarily think the IAC is bad, it might be bound up in carbon. The air passages could be blocked by carbon.

 

[studigggs]

If you keep your foot on the throttle to keep the idle up (with the brake on) and then shift into gear will it stall out? I had a similar issue (didn't do it all the time, but quite often) where my 90 would die when putting it into gear. Ended up being a dying fuel pump .Ran and accelerated great, but did have that idle stall quirk. Fuel pressure gauge from AutoZone pinpointed it .

 

[livinginh]

If you keep your foot on the throttle to keep the idle up (with the brake on) and then shift into gear will it stall out? I had a similar issue (didn't do it all the time, but quite often) where my 90 would die when putting it into gear. Ended up being a dying fuel pump .Ran and accelerated great, but did have that idle stall quirk. Fuel pressure gauge from AutoZone pinpointed it .

I have the gauge, I'm headed over tomorrow to check it out and try the different suggestions given. I'll keep you posted thank you

 

[tomb]

Any update?

 

[Vjcamp]

Perhaps your Idle Air Control Solenoid is not working/stuck and not responding to the change in engine load/gear

 

[honkon]

Figuring out whether it's running rich or lean during the stall condition would be the first step in narrowing this down. Not exactly sure how you go about that on these obd1(?) trucks.

 

[Vjcamp]

Figuring out whether it's running rich or lean during the stall condition would be the first step in narrowing this down. Not exactly sure how you go about that on these obd1(?) trucks.

YEP, hard to find Scan Tools that work with OBD1....I am lucky, happened across a TECH ONE GM Scan Tool that was for sale, so I snatched it up!

 

[livinginh]

Turns out it was the distributor, it was so worn the it would not properly advance when you put it in gear so it would stall the motor out. I've had this happen once before years ago and i had forgotten about it. Dropped a new one in, runs like a top now.
Thanks guys for all your tips