97 olds 88 3.8 stalling
 

Hey guys, got a 97 olds 88, that will randomly stall, like it was turned off, it also has another issue, i call, Insta-start

when starting cold, all i need to do is bump the starter, and it's running instantly, no cranking and cranking, starts on first spark... but when its warm, like go into store, and back in 5 minutes, it will insta start, but die, hit the starter, and has to crank over several times before it will start, then idle goes high and then normal

I cleaned the throttle body and butterfly, and the idle motor cone thingy, and was getting a clattery sound from the idle motor, so I put some oil on it and the spring area, no sound comes from that now, but still have insta start and hard to start hot, and intermitinant stalling, i turned in the idle stop screw and helped the stall issue, but still does it randomly, I have also cleaned maf sensor with maf cleaner, also unhooked battery, 30 min, then started car and let idle in drive until cooling fan came on to let it learn idle, turned off and restarted.. idles at right rpm and all, no codes, no check engine lights on,

checked all vacuum hoses, replaced the two little ones down on trans modulator, shifts very smooth and no vacuum leaks anywhere

two months ago, i had to replace middle coil pack, from misfires, had bad coil when checked with volt meter, 30 bucks and replaced coil and wires

car has 78 k, have replaced upper intake gaskets and new plenum (dorman)

car runs perfectly, except above issues

How can i reset the Stop Screw? fix Idle random stall, insta start? hard to start when hot issues?

any advise appreciated

I do have a volt meter
I have ran fuel injector cleaner threw several times

1st off, that idle set screw isn't supposed to be adjusted. Not even at the dealer level. Why it's their is beyond me. Even the FSM says not to mess with it. All idle is controlled via the PCM. Again, never adjust that screw. So, put it back where it was originally.

Your stalling is due to some other factor besides that set screw. Again, put it back.

Read this and see if it applies to you...
https://www.gmforum.com/electrical-1...1999-a-303224/

the pics are missing on the ground message.. but will look

as far as screw stopper, no idea where it was set

when its warm and going to do the long crank see if it starts easier with like half throttle, this bypasses the iac, and will point you in that direction or if not somewhere else

yes indeed, that is what I do, just push down on gas pedal and fires right up

so, do I need to replace IAC motor? after cleaning the throttle body, the IAC was making serious clattering noise, so I removed it, did some extra cleaning and took a scuff pad to the tip, then used a little motor oil to lube it, the tip and the spring on the back side, placed back into TB and fired right up, no clattering since, but still had insta start and and when hot, it was still harder to start, as if flooded, crank, hit and stuble to die, then crank for 2 or 3 turns before starting, reving high and then back to normal, if you press on the gaspedal a little, it fires right up when starting hot

thats what it seems like to me if you have already cleaned where the iac seats. i would put the tb screw back were it was too that may just goof up the pcm. idle air and rpm is controlled by the iac only. the butterfly controls from after idle to WOT.

Since a new IAC is required, I would buy Delco IAC only.

delphi or delco i normally get, both are like oem. its only like 30 bucks vs 20 on rockauto, seems worth it to me. alot of the cheaper parts dont run right or last long

thinking of column =ignition switch??