Damn cold start problem just won't go away... Engine runs just fine above 100* indicated coolant temp, but occasionally dies after a warm start.

TPS voltage is right in the middle of the range.
CTS works fine (been too damn cold and snowy here to actually DMM the damn thing). Same issue with the IAT sensor.
NO vacuum line leaks except for the EGR solenoid (small crack at a fitting.. will fix with glue) and tube (plugged the hole in the plenum... bolt holes are stripped) the two injector rings I have yet to replace (I have the rings just has been too cold to do anything about it).
Can't tell you about the timing right now... I don't dare take off the crank pulley right now, even though I have the puller, so I can replace the 3.1's balancer... I can tell you it runs just fine when it wants to and has lots of power when I want it.
Cold start injection works just fine.
No codes except for a code 32 when at highway speeds for more than 5 minutes at a time, because the EGR is disconnected at this point.
Plugs are brand new ACDelcos. They are almost normal in color except for the fact that thay seem to be mostly off-white with a small brown spot. I'll try to get a pic soon. Wires were new last January and were resistance tested a couple of months ago. The bad wire was thrown out and replaced with a good wire from an old set. Coil checks out okay. Cap and rotor were replaced with wireset. No evidence of arcing exists.

 

Okay, I think I might have finally found the problem. Anyone know how to test the IAC, or if it even can be tested?

 

its not even 20 bucks, just get a new one

 

Actually, it's 30 bucks. I went and got one... it still don't work as far as I can tell...

 

ouch 30 dollars american? cost me 29 candian to get a new one, don't forget to clean out the iac passage as it gets fairly clogged with carbon

 

IAC passages are clean. Anyone reading this have a 1227302 ECM they want to get rid of? The one I bought to replace the one with a permanent code 54 don't run the IAC... But the old one does...

 

... that's so wrong
I'd offer up mine, but I gotta keep it in case I decide to go back to stock...

 

Don't laugh at this thought BUT
it could be power steering hoses!
On mine the PS sytem also controls engine operation. As in too low pressure & the engine wants to "die/sputter".
I have a bad cold start injector, too. My vehicle runs too rich (cold) and it causes engine to "cut out" under certain "pedal pressure" (except basic wide open throttle & extreme gentle pedal pressure).
Once engine warms up, engine operation "just fine". But in parking lots, it "wants to die" and I know I have a PS hose problem as it's greasy.
And I also read that the PS system has an engine cut off sensor, too.
Things to keep in mind & hope good clue.
GM DOES HAVE PS FLUID for extreme cold climates.
How is skiing to work, these days?
My car does give a code reading for bad CSI and I plan to replace that very soon.

 

First off, I KNOW the IAC control in the only usable ECM I have is bad, because the other one works.
Second of all, I think the only reason my PS pump is so damn greasy is because my A/C sprang a leak, as there is grease all over the back of the compressor too. How would I go about testing this switch? Is it the one I am thinking of that runs along the frame right next to the steering column? I check the PS pump about once per week and I know for sure it's full...

 

I wouldn't say "TESTING" the sensor.
As I'm sure it's OK.
I'd more (LIKE MYSELF) replace the leaking hose, which I beleive I must do, too.
"THINK" vacuum leak problems! for the thought as to why that PS sensor may also be contributing.
I offer no more theory, than guessing. Besides I also need to do a full on tune up, from Oxy sensor, to plugs/cap rotor & the cold water temp operation sensor. Haven't done that in LONG TIME & I recently lost my CC due to overly rich cold engine operation. And I throw that Cold engine sensor code, too.
Hope it's a clue!

 

Now, is this thing mounted in the PS lines a sensor or a switch? I tested it for resistance and with the engine running it is still open...

Full tuneup has been done. CTS has been replaced. Vac lines don't leak, and I will be replacing the injector o-rings tomorrow, as it is finally warm enough for me to do so. I have finally sealed the damn air box thing for good, and if it still ain't right I'm going to the junkyard anyways, so I guess I can grab one while I'm there.

There is still the matter of the ECM thing though... I know for sure that the guy at the junkyard I've been going to is going to rip me off if I go there, and that is the only place that has any thirdgens at all within about 75 miles.

 

post in the classifieds that your looking for one, you'll probably get a response quick. I usually ask about something someone else is selling and a few people offer the same thing for less.