Help! Car starts, runs, dies on restart!

[dbritt]

Ok, so I go out and get in my car after it has been sitting dormant for a few hours and get a fresh start. Most of the time it will start fine like this. I'll let it warm up for a minute, drive it for even a little bit, park, and cut the ignition. After I come back from doing whatever I was doing (let's say picking up a hot date) and try to start the car, it cranks and then dies immediately if I don't keep my foot on the gas. What's the deal? Something that may be related to this is: if I do everything except park and cut the ignition and I instead go into an idle (fast food line), the car will start to die by the time I reach the window to pay. I've looked this up in here before but not found anything promising. Help please!

TIA

 

[CurtTSI]

I suspect that you have a bad ISC servo. This is exactly what mine did when my ISC went bad. ISC is located on the lower left side to the throttle body. Disconnect the 6 pin connector and measure the resistances between the 2 center pins and the pins on each side of them, 4 measurements. Resistances should be between 28 and 32 ohms. Take measurements when the engine is warmed up since the ISC will sometimes test good, when cold, but bad when warm. If you find that one or more of resistances is very large, open circut, the ISC is your problem.

 

[dbritt]

I tested it just now and got 45-50 Ohms for each of the 4 tests...

Is this far enough off to be causing the problems I described?

If it is the ISC, then I'm gonna be kinda ticked-off cause I just bought that one off ebay and it tested fine when cold (like you suggested).

 

[dbritt]

Here's the VFAQ for testing the ISC:

http://dmtalon.v8eaters.com/ISC.html

It says:

Note: The values should measured with the car off and cool!

So this makes me think that maybe the higher Ohms are OK while it's warm, maybe.

 

[CurtTSI]

I think that it's OK, since the resistances normally test higher when hot. Since they are all the same, it is probably good. When you test it, make sure that it is warmed up and the car is experiencing the problem you described.

 

[dbritt]

Well I didn't test it while the car was RUNNING, but within 5 minutes after I turned it off and it was giving me the problem even as the turbo timer was counting down...so that fulfills the requirement of "still experiencing the problem" I would say. I don't think it would be any better/worse if I did it while the car is running, right? If this ISC is fine...what else could the problem be? AFC misconfiguration? Something else?

 

[dbritt]

The problem was the idle switch not reading correctly. Needs to be conductive while no throttle, non-conductive while ANY throttle (it's very touchy). I suggest this be one of the FIRST things anyone checks when inspecting an idle issue because it's FREE to fix (unless the switch is just bad...which would seem rare).