1G Misfire and Stalls

[l3LacK Tsi]

ok heres the deal i have a 91 eagle talon tsi fwd after i start the car and let it heat up if i hold the idle at about 1500 to 2000 it misfires or atleast sounds like it misfires and after i let off the throttle the idle dips from about 1000 to 350 or so and then ends up stalling out also stalls while driving after coming to a stop. im looking into getting the tps and isc but does anyone think it might be something else also. any ideas would be great. it has brand new ngk plugs and wires.

 

[DSM90AWD]

Check base timing and Intake for leaks. Have you ever changed your fuel filter?

FYI.. the ISC can be cleaned and reused if you want to save some $.

 

[l3LacK Tsi]

how do you clean the isc? i took it off and checked the gaskets etc dont see how you could clean it. i gotta check timing and replace the fuel filter which was gonna get done this weekend along with a few other basic things like belts and what not. i checked the intake manifold for leaks at the head and throttle body also the brake booster but didnt find anything. i also took the biss out and cleaned it and checked the o-ring it looked good.

 

[l3LacK Tsi]

ok checked timing and its good still no fuel filter but i removed the throttle body took out the isc and tps used some intake cleaner and cleaned the isc but still no response from it even when i take the plug off it the idle doesnt change. also made sure i have a good seal at the elbow and throttle body so no leak there or at the manifold. i removed the heat shield from the upper exhaust manifold and found a hairline crack so i sealed it up but that didnt help anything. i got some vaccum diagrams from alldata and a few ground locations im gonna check. fuel filter will be installed tomorrow so ill update on that. i noticed the inside of my intake manifold was dirty so planning on doing a induction service to see if i can clean that out a bit. any other input would be great

 

[DSM90AWD]

how do you clean the isc?

Looking inside you should see a needle that seats on one side. There is a coil that retracts this needle to allow more air to bypass the TB to control Idle.

Over time crud builds up on the needle and seat that prevents it from fully opening/closing. To clean get a can of carb cleaner a paperclip (or other small pick) and clean as much of the crud out as you can.

I've had to do this 2x now on my 15yo 130K mile DSM and has worked liek acharm both times.

FYI.. if the ISC is indeed bad this wont help so may want to also check the VFAQ to test it.

 

[l3LacK Tsi]

dont think i cleaned it that well. ill take it off again tonight and give it a try thanks