BlackBird87

iTrader: (6)

As the title states the car misses at a steady state cruise 1300-2000 and produces and slight buck put more that i can feel cylinders dropping out. I have checked everything ignition and fuel related. I have talked to ion and he sayes there is nothing wrong with his tune but i think different, not saying he doesnt know what hes doing or that he f*ed up but it might need to be tweaked. Im just looking for input on what could be going on.

96blackz28

iTrader: (3)

while it could be then tune perhaps, but I had a similar problem and it turned out to be my o2 sensors. Just a thought.

RamAir95TA

iTrader: (2)

A datalog of the car during the issue would be invaluable in determining the problem.

1994Z28Lt1

iTrader: (1)

i had a very similar problem a couple years ago, did you physically pull the coil wire and check for corrosion on either terminal? Mine ended up being the terminal on the coil was corroded and cleaning it up fixed the problem.

What leads you to believe its the tune? were you driving smoothly on monday, switched to the reflashed pcm tuesday, and notice it running poorly on wednesday or what?

do you have a SES light? what codes?

did you physically check all your plug wires it doesn't take much for a wire to lay on a primary tube, and even a burn hardly noticeable will cause a miss under low rpm, high load conditions.

BlackBird87

iTrader: (6)

I have tunerpro but im in the process of trying to figure out how to input my a/f during the log

I put in new plugs and plug wires everything was cleaned before final install, nothing is burned. I have no ses light. I bought this car as a roller with the engine and trans out of it and rebuilt the motor i only drove it a few miles before i got it tuned but i didnt notice any misses before the tune. I also got about 12mpg driving very conservatively

JAKEJR

A scan should tell you. Your intergrator and BLM values will show it if the engine's running lean. I'd first suspect spark arcing to ground. Could be a plug wire or boot. Plig wire too close to the ICM, ETC.

A member on another Forum just found his Opti was arcing right from the distributor to the water pump. He couldn't see it at first because it was happenng BEHIND the water pump. Then he removed the water pump and held it close to the Opti -than ZAP!!

Jake

BlackBird87

iTrader: (6)

Nothing is arching ive ran the car in pitch black darkness at all rpms

gregrob

iTrader: (8)

Speaking from experience, that wont always find an arc..

mrchyzy16

iTrader: (1)

+1 on o2 sensors. I had the exact same problem happen of one of my other cars and it ended up being the o2 sensor. Are you getting any codes?

SS RRR

iTrader: (2)

Unplug the O2's and see what happens. If it still does it, plug them back in and carefully check each and every plug wire as well as the coil wire. Check to make sure the water pump is not leaking onto the opti.

396b4c

had the same thing happen. ended up being my msd coil taking a dump

djjab57

iTrader: (17)

I couldn't see an arc either BUT 2nd one one the passenger side I couldn't see because it was under the header. Just saying might want to feel the wires real good.

wrd1972

iTrader: (12)

Get a spary bottle with some water and put a fine mist on the wires and the opti. This will find any arcing.