273sunsetZ

I used hptuners today and it came back that cyl. 4 & 5 were misfiring, so i replaced the plug wire and plug on 5 scanned it again and it didn't help... Anyone know of what i should try next? I check the history of cyl. 5 and its had almost 60k misfires...

But thing is, when i get the rpm's to 1600 the misfire goes away... I also swapped a coil pack from cyl. 1 to 5 just to make sure it wasn't bad and it didn't change a thing.

Eddie 70

iTrader: (3)

TTT

Anyone got any ideas on this?

My son is having a misfire issue with his car. He says it will quit misfiring when he is on the gas around 3000 RPM and then when it straightens up he says it the car runs really good. This low speed misfire is killing the around town driving. We have changed plug wires and plugs and this has not changed anything.

Thanks for any help.

Eddie 70

iTrader: (3)

My son just told me another tidbit of info, he says it stumbles as long as the car is cold. When it gets warm is when it starts stumbling.

TLewis4095

iTrader: (10)

sounds like injector issue....how many miles on the injectors? You may want to swap them to other holes & see if the miss follows.

thebart455

if its only on one cylinder you could have a clogged fuel injector, pull the #5 fuel injector out of the intake and see if it gummed up any. if that dont work you may want to have a compression test done on the cylinder to make sure theres not a problem with the cylinder

Eddie 70

iTrader: (3)

Just to add to the thread so I can close out our part of this problem. We cured the miss by replacing the O2 sensors and it is fixed. He drove it the last two days and reports no misses and no problems. He actually used rear corvette 02 sensors as replacements for the front sensors on his camaro.