HELP!!! Random missfire?

MADED-6 · 11-06-2008, 06:07 PM

Well i got another muffler put on last wednesday and ever since at betwenn 1/4-1/2 throttle the car just misses really bad now it has new spark plugs new leads and i have tried another set of coilpacks.
im not saying it is the exhaust causing it but thats when it started happening.
it is alot worse in the morning as in nearly undriveable just doesnt want to accelarate and sometimes even feels like it has stalled but it is just not accelarating.
i was thinking maybe maf sensor stuffed but then it would run rich when it is happening but its not throwing any unusual black smoke.
i also thought headgasket but then it would do it all the time.
when i say 1/4-1/2 throttle i mean it misses then u accel a bit more and snaps u in ur seat and takes off.
i am completely lost to what it could be but any suggestions would be muchly appreciated.
Cheers Josh.

b2tf · 11-06-2008, 06:08 PM

Josh, did they disconnect the battery when they did the exhaust work?

MADED-6 · 11-06-2008, 06:44 PM

nah they didnt whys that?
cheers josh.

RG · 11-06-2008, 07:37 PM

Disconnect it for a half hour and let the computer relearn. Mine is a pig in the mornings too, has been since the stroker and acts the way you described. Nature of the beast I think.

MADED-6 · 11-06-2008, 07:39 PM

yeah ill try that also i thought i might add when i start it i always pump the brakes b4 i put it in drive i dont no y but i do and if i do that it stalls on me which sort of hints vacuum leak to me.
also cant i just put the capa flasher tune back in it as that resets the ecu anyway.
cheers josh.

RG · 11-06-2008, 07:50 PM

Quote:

Originally Posted by MADED-6

yeah ill try that also i thought i might add when i start it i always pump the brakes b4 i put it in drive i dont no y but i do and if i do that it stalls on me which sort of hints vacuum leak to me.
also cant i just put the capa flasher tune back in it as that resets the ecu anyway.
cheers josh.

Yep, do that with the flash tuner.

MADED-6 · 11-06-2008, 09:02 PM

well just found the pcv was basicly hanging out of the motor fixed that still did it so i plugged the capa in and flashed the run in tune back into it and seems better but wont speak to soon.
cheers for ur help boys.
cheers josh.

MADED-6 · 12-06-2008, 06:32 PM

well its not gone its the same when cold and doesnt do it when hot unless u turn the car off then get back in and go again.
i took the maf sensor out tonight and cleaned it with some contact cleaner incase there was some stuff built up on it.
seems to be going harder i must say tho so something has worked lol.
cheers josh.