I believe I made a topic about this issue once before, but couldn't find it in a search. I have an update, and need some assistance solving the rest of the puzzle.

The issue: Upon starting the car (88 245) the FIRST time the car reaches approximately 1800-2500 RPMs the car cuts out for about 5 seconds. It doesn't matter if I'm in neutral, first gear, second gear, ect. Generally, when I start the car, I just go ahead and rev it up and let it cut out so I can drive. It will not happen again until I turn the car back off. I can drive 300 miles and it wont happen again, but I can turn the car off, turn it back on, and it will do it again, ONCE. I can even repeatedly turn the car on and off and have the issue. By cutting out, I don't mean bog down or spit and sputter, it literally cuts out instantaneously, like no throttle response what so ever, for about 5 seconds.

What I've done: I replaced the distributor (because clips were broke, not because I was trying to solve issue), cap & rotor, and timing belt.

What I've solved: If I disconnect the idle air control valve, the issue does not happen. I tried plugging a new idle air control valve, and it still had the same issue. I also tried plugging a different ECU in, and it still had the same problem. Yet, if I cruise around with the IAC valve unplugged, I never have the issue.

What I'm needing help with: What could possibly be the issue between the IAC and the ECU that would cause this issue? It is not the IAC or ECU, and I don't have any other symptoms that would point to IAC or ECU. The car runs GREAT, just purrs along, except for the first time it hits 1800-2500 rpms. Any ideas on how to continue the diagnosis?

 

make sure the idle switch is working properly. clean/ungunk the throttle body. make sure there's no air leaks between the throttle body and the MAF/AMM.

with the idle air controller unplugged, at what speed does it idle once warmed up?

 

About 900 rpms rright now.

 

Of course, I can adjust it though on the throttle body. Also, I can plug in a good IAC, but not hook it up to the vacuum hoses and still have the same symptoms. Car runs the same with it plugged in, unplugged, or a dummy IAC plugged in, not hooked up. Only difference between plugged in and not plugged in is the unusually cut-out symptom at 1800ish rpms.

 

900 is high, unless it was in warmup mode. they should be idling around 600-700 rpm when warmed up, a/c is off, etc.

next time you start it... see if the alternator light is still on... when you rev it up to 1800 rpm and it stalls, what does that light do? does it go out almost immediately when you come off idle, long before the car stalls/hesitates? or does it go off right when the car hesitates/stalls?

 

Alternator light is not on. Volt gauge reading is somewhat unpredictable, reading about 12 volts after starting, and gradually climbing to 14. Sitting at idle and rev ing motor does not generally bring it to 14 faster, after I drive around while it'll get there. Sometimes, it is right at 14ish upon starting. New alternator and voltage regulator within last 18 months. New, not rebuild.

 

Also, I thought standard warmed up idle was about 750 - 800 in 88.

 

does the alternator light come on before you start and go out as soon as it starts?

then its good. never mind this.

 

Yeah, no issues with alternator light staying on.