92 eagle talon running like junk. (maybe non-firing cylinder)

[blueninteytwo]

car's a 91 eagle talon tsi (auto) with 106K on the clock.

2 days after I put fresh NGK plugs (br6es's, one heatrange colder than stock) and fresh NGK wires, the car ran like a dream for a day. I let a buddy of mine drive it and he gave it back with no problems (he says).

i get in the thing to drive it and start it up, and it runs like crap. i'll explain to you the situation.

1. sounds like 1 cylinder isn't firing. you can hear it in the exhaust note....sounds like the last car that didn't have all the cylinders firing.

2. sounds like a harley. at low rpms, it idles ok, (doesn't stall out or anything) but it shakes the whole car. you can feel it.

3. it's very slow to respond to throttle input... has a real hard time making it up steeper hills.

4. it tends to backfire on me. not loud, but it's doing it.

5. SUPER IMPORTANT: only does this when the car is warm. when the car is cold, it runs fine, when the car warms up, runs fine, but as soon as you shut the car off and turn it over again, runs like crap. so as long as the car started out cold, it'll run fine, no matter how long i drive. but as soon as i turn it over again, it runs like crap.

turbo spools (you can still feel it) and tranny shifts fine, but i'm lost.... the last time the car ran this bad is when the ECU fried itself and only put out 7V for reference voltage to all the sensors.....

i'll check the wires with a timing light to make sure they're firing when i get out of work, but maybe you guys ahve seen this before...

 

[marcmsj]

Check the spark plug wire connections, both and the coil and spark plugs and report back.

 

[blueninteytwo]

good answers folks, turns out the fuel injector dies when the car warms up. replacing injector hopefully over the weekend.

 

[95 'clipse RS]

not to say that that isnt what it is, but youre problem could lie someplace else. the ECU uses various sensors to determine when the injector fires, and how much fuel to spew. some are front o2 sensor, engine coolant temperature sensor(not the coolant temp sending unit), mass airflow, and intake temp sensor just to name a few. just thought id throw those out there incase the problem lies eleswhere.

 

[blueninteytwo]

yah, i'm pretty sure it's the injector. it's just not firing, i can hear it... it's not a misfire of some sort, it's just plain not firing.

plus I took the wire from the #1 injector (the one that's bad) and unplugged the wire from #2 injector and plugged #1's wire onto #2 and fired the car up. ran and ran well (well as good as it's gonna run for being plugged into the wrong cylinder) and checked for operation with a mechanic's stethoscope.

if there was a signal issue then i doubt the car would have ran at all....

 

[95 'clipse RS]

you'd be surprised what misreading sensors can do to a car, and it still run. and i dont think unplugging #1 injector and plugging #2 in it is the best way to tell, since they both are meant to go off at different times. timing is essential throughout the entire engine. but i wish ya the best of luck man.