You could , as a test.... unplug the cold start & put a fixed resistor in to sub for the ECM temp sender...

Might a a chore to start STONE COLD... but it would help prove a point...

Mike

 

I would be looking at fuel pressure and the filter. Rust in the tank can cause this on again off again running. As far as the cold start injector you might want to remove it and block off the line. The injectors themselves leak, unplugging the electrical connector it still gets gas which can leak and flood you out.
How do your plugs look?

 

Try switch the connectors for the cts and thermotime switch. The cts does go bad and this kind of problem can happen. If,after switching the car runs longer,replace the cts.

 

afm flap could be stuck open some times. I got 78 z it would run fine then run rich when i stop. take cover off afm . Finger the weight open see if flap swings free. Start the car look at afm .see if it sticks at any certen point. Turn car off see if it clsoed all the way. IF it sticks spray lube in afm and one drop at pivot point on the circurt side . best done with amf off car were you dont make a mess of it. http://www.youtube.com/watch?v=KASscLNHhhI&feature=related

 

YES... ( Boy did I miss this )...
Fuel pressure gauge..... report back....
AND
Where do you live... east coast... west coast??
How long can you drive it....( in miles ) before it poops out?

Mike

 

Definitely check fuel pressure differences between when the engine is cold and when its warm. Now I dont know the exact reason why (although if someone could explain it that'd be appreciated) but with the current faulty fuel pump I have on my car right now the car turns right on when its cold but when its warm the fuel pressure dissappears when you try to start her up. JoelR you might have the same issue of the fuel pump not making or holding a constant pressure. Also (and I know this is pretty unlikely) you might want to look into vapor lock.

 

Thanks for the responses. To answer a few of the questions & clarify:
1. Gas tank is clear and fuel filter is new.
2. Car is running rich - not starved of fuel - so I'm not sure fuel pressure is the issue.
3. I was able to make a short loop around the parking lot - not far (much less than 1 mile).
4. I am on neither coast - in Texas (DFW).
5. The plugs are gettting fouled, so I keep cleaning them off.

A little background: Been driving this car regularly for the past 10 days (total of about 2000 miles since April). Drove the car to work just fine Tuesday morning. Tuesday afternoon it cranked up but idled way too rich and too low rpm - tons of smoke out the back when throttle opened. Cleaned off various connectors. No change. Wednesday morning (in the 60's) it cranked up just fine and idled right. Shut it down and proceeded to clean ALL FI connectors. Wed mid-day (upper 70's), rich idle, smoke with throttle. Ditto Wed late afternoon (mid 80's). Thursday morning inspected cold start valve per FSM - not leaking. Thursday mid-day (lower 70's) cranked up fine and drove around parking lot until it died (no more than 5-6 minutes). Failed to re-start after that. Cleaned off plugs several times in the midst of this exercise. Air temp and Coolant temp sensors were reading in the correct range.

 

Was it blowing white or blue smoke? You could be burning oil or coolant. Are all the plugs getting fouled or just certain ones?

 

UNPLUG YOUR thermo time switch ( or the cold start valve ) and try again....

Have you measured your fuel pressure??
and look & smell the dipstick... is it getting HIGHER and does it smell like fuel in the block??
Mike