If anybody out there can lend a hand, I would greatly appreciate it. My '86 Iroc dies, when put into gear and light throttle is applied, when the engine is cold. It won't quit stalling until it's at FULL operating temp. Here's what I've checked already:

TPS - .57v
No codes from ECM (new ECM), checked with Snap-On scanner
IAC set to 28 MM, no heavy carbon build-up, drops fine on deceleration
Idle smooth - 550 in drive
MAF okay (no codes)
No vacuum leaks found
Stock PROM - OK, Stage 1 PROM (WOT) - OK
Timing set at 6 degrees
New fuel filter
TCC disconnected for giggles, no change
Plugs, cap, rotor & wires in good shape
New O2, works fine (checked with scanner)
Fusible links are okay
ECM ground is solid

Like I said, it works beautifully when at operating temp, so I can rule out the TPS. I'm stationed in Okinawa, Japan, so running down the street for parts doesn't happen. I need to actually "fix" this instead of playing "hit-n-miss". If anybody can suggest something I may be missing, I'll be your best friend!

Thanks,
Ted

 

It's only when you push the pedal in gear? Or just when put into gear?

Could be the coolant temperature sensor, connection problem there is more likely than sensor failure. That would affect the acceleration enrichment, especially when cold.

Does it stall like right now, or is it a slow death?

If you adjust the throttle blade more open will it still stall cold?

 

It's a smooth transition into drive, no surging. It usually dies when the throttle is slowly applied. It goes like a bat out of hell when punched. But this morning, at a green light no less, it died as soon as it went into gear, no throttle applied. It ran great in neutral.

The CTS was giving off a code 14, but only because the wires were touching (no connector on the harness, just wires with ends). After that was fixed, the code went away but the problem remained.

It's a sudden death stall, no leading up to it.

Today I put the stock PROM back in and adjusted the IAC to 28mm, which brought the idle down from 725 to 525. It would stall coming off of deceleration so I adjusted the throttle set screw to bring the RPMs up to 575. Unfortunately, the engine was warm when I did that so I'll have to check for a stall in the morning. Who knows, that may have fixed it. But if it didn't, I'll need to dig some more.

I thought about the module, but they usually go out all at once. The fuel pump came to mind too, but that doesn't explain why it runs fine warmed up.

 

Heres a wild guess because I had a similar problem with my 88 GTA....at least it used to run like @ss when cold....the cold start injector or cold start valve was not working so the motor was running realy lean when cold and not getting enough fuel. I unplugged the cold start injector's wire and upgraded my ECM's prom to that of an 89 corvette. 89 and up the cold start injector was no longer used to 'choke' then engine on cold startups and instead the motor used the existing injectors to dump extra fuel into the cold motor.....thus getting rid of the cold start valve. Check this thread, maybe it will help:

https://www.thirdgen.org/techbb2/sho...hreadid=315363

My 88's 350ci still runs lean and a little rough on cold days, but I think its because of a vacuum leak or bad egr valve and a poorly set TPS sensor.....I will post the results of my car after I replace the injectors, EGR and TPS this weekend (on the "running rough when cold" thread)

Hope it helps, there are many aspects with TPI engines that are associated with getting a good idle, right now its my mission to get it resolved and post some results considering this is a problem for many TPI owners.