Bad Misfire. Help please.
Bad Misfire. Help please. Alright Guys first I had a no start condition, discovered the rotor had fallen off of my GM opti. Replaced the opti and now it starts but I have a bad misfire.
Vehicle starts up pretty easily and sometimes will idle okay for a little bit but then it goes to missing. When revving it you can tell its not as smooth as it used to be.
It normally starts to get worse once it starts and it will backfire really loudly and sometimes kill the car.
New parts
Opti (Reman Cardone. Age: Less than a week)
Wires (Summit Racing 8mm. Age: 2-3 Weeks)
Plugs (NGK TR6. Age: Same as wires)
ICM (Borg Warner. Age: Same as Opti)
Coil (Borg Warner. Age: Maybe a year)
I went over the car and made sure I had no loose plug wires. All good. Checked for chafed or burned plug wires. Nothing.
I did notice the connector on the opti end of the harness is a little damaged but it seemed to plug in just fine. Wiring of the harness is fine seems to isolated to the actual connector.
Do yall think the conector is the problem? Could it present intermittently like it is for me, or should I be looking at something else
Vehicle starts up pretty easily and sometimes will idle okay for a little bit but then it goes to missing. When revving it you can tell its not as smooth as it used to be.
It normally starts to get worse once it starts and it will backfire really loudly and sometimes kill the car.
New parts
Opti (Reman Cardone. Age: Less than a week)
Wires (Summit Racing 8mm. Age: 2-3 Weeks)
Plugs (NGK TR6. Age: Same as wires)
ICM (Borg Warner. Age: Same as Opti)
Coil (Borg Warner. Age: Maybe a year)
I went over the car and made sure I had no loose plug wires. All good. Checked for chafed or burned plug wires. Nothing.
I did notice the connector on the opti end of the harness is a little damaged but it seemed to plug in just fine. Wiring of the harness is fine seems to isolated to the actual connector.
Do yall think the conector is the problem? Could it present intermittently like it is for me, or should I be looking at something else
If that 4 pin connector on the top of the Opti is melted or corroded (I've had both!) then that will cause missing and it may or may NOT through codes - with both of my bad extension harnesses, I had zero codes. If you pop it off the body of the Opti and the terminals are green, then I'd bet you've found your problem. BTW - the GM part is $140, but I found them on ebay for (if I recall correctly) less than $40.
Good luck!
Good luck!
I had an issue with mine for the longest time. Ran rough like it was missing on 2 or 3 cylinders and replaced the opti, coil, wires, etc and turned out it was bad O2 sensors. Try unplugging the connector and if it runs normal (although will be in open loop) its your O2s.
Ill try all that tommorrow anything else I should look at.
Ive already ordered the connector it will be in tommorrow. So ill put that in, if i doesnt fix it ill try the 02s. Although they are pretty new so I doubt they are the problem.
Ive also gone all over the fuel system its fine.
And unplugged the maf and made no difference, so im pretty sure its ignition related.
Ive already ordered the connector it will be in tommorrow. So ill put that in, if i doesnt fix it ill try the 02s. Although they are pretty new so I doubt they are the problem.
Ive also gone all over the fuel system its fine.
And unplugged the maf and made no difference, so im pretty sure its ignition related.
