Newbie here in the forums. Sportin a 91 rs. A ride I have had for some time now.

I got it for $400 6 years ago. Let my Son drive it for about a year and a half. His first car. He had issues with it and gave up on it.

Saw some serious maintenance woes. I have it back now. I gotta say This was a nice ride.
I loved driving it and I will again. Plans' ? Hmm well ?? I have been eyeballing the hybrid postings.
I wont entertain the idea of dropping a 8 in her. I like my 6. Plus I am enjoying the build. I have been reading everything I can find in the boards as getting a proper tune-up on my baby.
I really messed up the first time it seems.
The heater fan was on and I turned the steering wheel. A big no no from what I have read.


Fixes and Mods
replaced Idle control motor (ICM)
TPS
re-installed 02 sensor
re-set timing back to factory 10*
re-installed air intake duct (was missing )
patched together a "severely" botched exhaust (cat was cleared out and then looks like the rest must have high centered or struck something?
fixed short in the steering column
found a nice aftermarket rear sway bar. planning on installing soon.
took out sagging headliner

Issues and problems

Someone drilled out the idle adjustment cap and has been messing with the factory setting. (looks like they bent the strike plate for it also)

factory tachometer is faulty ( it works it just reads 6200 @ low idle of 700 (from hand
held )

surging idle seems much better now that timing has been adjusted.

engine stalls under load. It ran but still stalled and or overheated at stop signs until I adjusted the timing. Now It wont drive unless in re-learn mode. in re learn mode it runs like a beast. good throttle response ,nice idle, clean acceleration/deceleration. But as soon as 20 min are up she stalls and wont run under load until I unhook the battery wait for a few min then hook up and go.

I have read most of the boards here regarding tuneups and repairs. I am used to old time tuning. Not this electronic witchcraft. So I get a lil lost at times.

Anyone have an idea where to start? I was thinking new fuel pump filter and adjustable pressure regulator.

Am I on the right track?

 

I'm thinking IAC, try cleaning the throttle body up, take the IAC out and clean that passage out. When you replaced the ICM did you coat the underside with dielectric grease/silicone? If not it could be that its overheating and stalling the car out, could also try adjusting the TPS a bit, and check for vacuum leaks.

 

Thanks 3rd gen doing that now.
I adjusted the IAC and the Idle smoothed out nice. I am not sure if I did it correctly though? I saw a post somewhere about how to do it right. I just got back from getting a can of carb cleaner so I'll keep you posted on the vac leaks
It sure does feel like a fuel problem though

 

Yay !!! no Vaccume leaks!!!! no codes thanks 3rd gen she runs like a scalded dog. it was all in the TPS

NOW THE FUN BEGINS!!!

 

Tune up and adjustments completed

CHILTON VS HAYNES manual Chilton for break down and exploded views. Haynes is kinda vague but trouble shooting guide is useful for first time owners or simple where to look guide.

OK Back to my question
I got everything back together and felt fairly confident to take a longer trip.
120 miles
filled the tank
idle is still a little rough
throttle response a little sluggish. But not bad Been a long time since I drove the car I cant remember what it felt like before.
I would like it to be sharp ( I understand F-body is heavy so launch with a six isn't impressive) but it should still be crisp.

while driving at speed I turned A/C fan and rolled down the window. Immediately lost power. throttle became sluggish and then died. coasted to the side of the road. turned off everything sat for a minute or two.
Started up and ran fine. For about 40 miles same thing only this time no accy/ draw

poured SEA FOAM per instructions.

Stalling happened 2 more times. Only this time on the last instance.
while almost home at a stop light engine stumbled almost stalled then raced for a second. Smoothed out better than it ever ran before.
ran awesome all the way home.

Haven't checked it this AM

Obviously I need to change fuel filter and Possibly injectors

But what is going on with running the accessories? Am I looking at a short or a bad alternator?

 

Well it's common knowledge that when an accessory is on it draws power from the alternator simultaneously with the other parts of the car that are running. From that I suppose we can deduce that there may be a short going to the alternator, although why it died is beyond me, unless the alternator itself is bad. Maybe have it checked at a parts store like Autozone. Other than that I'll leave the rest up to the experts.

 

Had it checked at the local parts store everything checked out fine.

no codes on the ECM either looking for a short now. but everything seems to look really good. Good resistance with multi meter.

I would think ECM would throw a code ??

Just so I would have an Idea where to start.

 

Check the resistance of the fuel injectors... No less than 11.8 ohms per injector is acceptable. You may want to replace them (or send them out to be cleaned) if the car had been sitting for a while... Could be clogged internally.

There is an issue on the 90-92 cars in the ignition circuit wiring. GM issued a TSB on it. A user on here got a new engine harness out of it not too long ago.