why is car missing after tuneup ?
my 1996 grand marquise was missing on the number 2 and 5 so i paid a mechanic to
tune up . i went and picked up the car when i drove off it was running nice , it had more
power and no miss . i got about half a mile down the road and the miss came back , by
the time i got back to the mechanics it was popping , it is now missing on the number
2 , 5 , 6 , 7 , and 8 . the miss seams to go away out on the highway but as soon as i
get back to city driving it starts missing again . the mechanic says its nothing he did
and refuses to make good , i dont know what to do , please help
This sound,s to be a fuel problem,check fuel pressure could be fuel pump going bad,
Multiple misfires can be caused not only by spark, but by fuel and vacuum issues. Also valve problems in the engine as well. Have someone else diagnose it for you.
Agree with tom,to many way,s to look.
somebody was telling me about the coil pack or harness . they said if they were broken during tuneup that it would cause a miss fire . it is strange that it started missing on more cylinders after tune up. is there anything that could have been damaged during tuneup that would effect the fuel or vacum
If he replaced with new wire,s and plug,s,yes there is a possibilty that something,s not right,but you said it ran fine until you drove it,then it started,so may be check your coil packs,and crank sensor,then go for that fuel pump,,,Good luck with it
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