'91 GT w/3S-FE cuts out

[RoxorVoxor]

I want to state first I am a machine mechanic by trade and am just getting my start on cars as I have limited experience in troubleshooting/repair so forgive my lack of proper terminology. I just bought a '91 GT with the 3S-FE motor in it last week. I first had problems with it starting up and then when it would start up it would run either rich or lean, occasionally shut off at stops when in neutral and stutter in third gear around 2000 RPMs. I first replaced the O2 sensor, but this did not do the trick. I checked all my vacuum hoses and air intake for cracks and found nothing. I pulled off the throttle body and cleaned it up with carb cleaner. After putting it back on the car ran very rich idling between 1500 and 2000 RPM. I pulled it back off and checked the ISC valve. I adjusted the spring to allow the valve to close completely as it didn't seem to turn just right... no luck there. I adjusted the throttle control switch on the back of the throttle body and that allowed it to idle around 1000 RPM but the car still cuts out after about 1 minute or so. I did notice that the magnet on the valve switch doesn't seem very strong... could this be a possible culprit? Any help would be greatly appreciated.

[RoxorVoxor]

I messed around a little bit more today with this car just checking connections and all... couldn't find anything. I started the car up and it seemed to do it's cold start routine quite heavily going between 2000 and 2500 RPM's every 3 seconds or so.... it did this for about 2 minutes and then leveled out around 1000. I took it for a drive around the neighborhood for about 3 minutes. Everything was fine until I pulled to the corner right at my house... I put it in first and it cut out on me out of nowhere. A tiny puff of smoke came from the hood on the drivers side in the area of the air intake. It took a few tries to start it up but finally did with no more smoke. It then was revving between 2000 and 2500 again. Anyone.....

[TBayToyotaBoy]

You're describing a couple of different symptoms that may not actually be related. The loping idle and the stalling might be related, but then again may be separate issues...

Check that your EGR valve is functioning properly.

If possible, try pressure testing your fuel pump. If it's weak, then it'll inject foam from time to time (which, I admit, has never happened to any of the nine Toyotas I've owned, but is more common with Jeeps and some older GM cars).

The only time I had a smoke-in-the-air-intake-region symptom, my cold start injector was acting up and the car was extremely hard to start. I hope this helps, if only a little...

[fredk]

did it pop out the intake?