Misfire when cold? [Archive] - GrandAmGT.com Forum


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12-27-2006, 03:16 PM
I start the car up in morning in the winter now and it's super rough, check light came on, misfire on cyclinder 4? Everything appears fine. I have MSD wires, fairly new plugs.

Cleared the light. When I start car it runs rough,(Can tell its misfire) I rev it up 3 - 4 times to warm it up, then it runs mint rest of the day. (Only last about 10-20 seconds)

Coil packs? Sensor dumping too much fuel? Injectors are fairly new, ran lucos injector cleaner through them. Any ideas?

Thanks for the help!

12-27-2006, 04:36 PM
whats funny is im kinda having the same problem right now with those wires. I have the MSD 8.5. But mine only misfires when its wet out. And mine is cylinder 2. Idk if its the wires. My SES light comes on for a bout a minute blinking then it goes away

12-27-2006, 04:40 PM
I got mine from Dr. Speed While back. You get yours made by him, or a prefabbed set later on from MSD?

12-27-2006, 04:54 PM
I got mine from carparts.com i think

12-27-2006, 05:48 PM
If the SES light is blinking that means your doing damage to the catalitic(sp) converter. Your basically dumping too much fuel into the system and its not getting burned off.

12-27-2006, 08:49 PM
yea i know....but it only does it for like 30 seconds then runs great afterwards

12-27-2006, 11:12 PM
I hate misfires...

Swap the injectors around and see what happens. If that don't do it see if you can swap the coils around. I'm thinking injector. Might be leaking just enough to bleed off fuel pressure when the motor is off but not enough to affect op temp operations.