Warm engine stalls at start-up

[AlaskanDsm]

I have done some searching lately and I can't seem to find anything that answers my questions. If anyone can direct me to something else that reminds you of my problem please by all means direct me! haha

After I drive my car to somewhere once its up to temp and turn off the car and go inside everything is fine car runs great not issues. But when I get back in the car and go to start it, it turns over catches and then it goes from 1000rpm to 0 but it tries to catch it from going under about 700 but it still stalls... But if i give it gas it stays running with no problems. Sometimes if i start it it won't stall but catch at about 400rpm and then bounce bcak to 800-1000rpm and then kind of bounce back and forth a couple times between low and high and then settle at idle.....

I really don't know where to start diagnosing this. I have a camera and can take pictures and video if needed. I could really use some help. Thanks.

 

[jongreene]

Have you removed the fuel pressure solenoid? Or any sort of vac. line reduction?

 

[AlaskanDsm]

As far as I know everything should still be there. Also when I rebuilt the engine I spent 2 hours ripping out all the vacuum lines and rewiring them so that they were aligned with the diagram in my Haynes manual and they were all out of wack before.

 

[TheWanderer]

I don't know if the turbo vacuum lines are the same as the N/T, but if so, check your thermo vacuum valve lines. I am having the same issue with my 92 n/t right now, and it was originally a bad line running from the bottom of the thermo housing to the top of the throttle body. I replaced the bad one and it ran fine til the other night when another one went. replaced it yesterday when I was cleaning my TB. still having problems, but I think it may be either my EGR valve, charcoal can, or my manifold absolute pressure sensor.

When I figure it out entirely and fix it, I will give you more info, and see if that may be your problem also.

 

[AlaskanDsm]

I can take a look at my vacuum lines tonight and see how things look. See if anything came off. But I have been keeping an eye on my engine since the rebuild but its always possible that you can overlook something.

 

[AlaskanDsm]

I checked all my vacuum line and they all looked connected and they still seemed to be in good condition. I did some searching about possible ECU issues but My car didn't seem to fit any of those symptoms...thankfully.

 

[Auto RS T]

Did you try bumping the idle up a couple hundred rpm? This would help it to not stumble on startup and I am curious if it will help. Don't forget to ground the adjustment connectors.

You could look into the idle surge fixes.

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Maybe that video feed would help out a little...

 

[Noogabox]

This definatly sounds like a small vacuum leak. You manifold itself can be leaking or a injector ring could be rotted out. Look to see if one is leaking fuel. Mine have done the same thing. It throws a engine light and says it has a small vacuum leak. If I let the car sit all night and reset the ECU it will run perfect for another 3-4 days before it does it agian. I also found that my O2 was out. I replace the O2 and spark plugs and now the Idle is the best it has ever been.

Codename: Upgrade, Xbox 360 Talon
I am having my system smoked to find all the leaks. Then we will get them all ( or just one) at one time to fix the vacuum leake issue.

 

[AlaskanDsm]

well, I feel positive that its not an idle issue. The car runs perfectly outside of this little thing. I didnt think to check the injector rings but I will definitely take a peak as well as take a look at that video just in case.

 

[Auto RS T]

You can run a boost leak test off the TB elbow with soapy water to see if the injector o-rings are leaking. Spray the intake manifold gasket too and check for leaks. I would then continue to boost leak test the whole intake tract.