I have an 02 zo6. I have a missifre cylinder 1 primairily but the scan tool also showed there had been some in 3,5, and 7 as well. I have replaced a coil pack because I thought that was it, then all new plugs, and all new wires, I tried a new fuel injector. Here is what makes it very hard to diagnose. It will not missifire at all times. at idle it will only do it after it has been running for about 1 minute. when driving if it stays low in the rpms, below 2k, for a while it will do it but I van make it go away by giving it gas brining the rpms in the2k-3k range. I just replaced my o2 simulators as well and there is no codes for 02 sensors. the only code That is coming up is the p0300. There is also my service abs, service tcs, and service active handling,...and service column lock. I know thats a lot but im at my wits end with this car. If it helps diagnose any further everything but the service abs,tcs,and active handling all happened after I took it to have a new trans put in along with new clutch and flywheel. the shop was a nightmare to deal with so taking it back there is out of the question.
-thank you,
Eric

 

I'm sure you've probably checked this but in case it seemed too simple to be the issue I say it anyway. Double check and make sure your plug wires are fully seated on both ends. One of mine came loose while I was driving and created a misfire situation.
Good luck.

 

All misfiring on Bank #1?????????? Look just behind Injector #7, you'll see a metal bracket sticking up. Check the bundle of wires that run around that bracket. Been known rub through the insulation.

 

Some have had valve spring problems cause this, pull the valve cover for a quick peek.

 

+1. Same thing happened to me. Would get an intermittant miss. Reseated all my injector plugs, went away

 

Can you HEAR or FEEL the misfire ??? If not you may have a false misfire--Often caused with an aftermarket flywheel change---If that's the case then all you have to do is max out the "misfire tables" and it won't trigger---However then the only way to know if you have a real one is by your own senses--But you won't get any false triggers or misfire codes------

 

A real misfire for sure. I can feel it big time it loses power after being low in the rpms and i give it some gas and it goes away. I was using a snap on MODIS scan tool so I wasnt using a cheap pepboys thing. I checked the plug wires more often then i would like to count. for it being a valve spring im leaning towards due to the fact that it is not constant and goes away if i get on it. im going to check behind cylinder 7 for those wires. Any thoughts on the column lock as well? it just says service column lock...nothing else is affected though...the steering wheel hasnt locked up and its been on for 4 days now.

 

could you be having problems with a crank position wiring to the sensor? On many cars this sensor and its wires are in the area of the flywheel. This can be damaged during trans R&R and cause all kinds of problems causing ghosts in other areas.

 

Thank you for all the responses, I am going to be checking the wires behind cyclinder 7 today. Seeing as it seems a little odd that its only recorded missfirs on 1,3,5,7 and none, not even in history on the other side. I let you guys know what I find.

 

I had exactly those symptoms, and it was fixed with a new injector. I realize you said you tried that already...

I guess fuel enrichment at startup increased flow enough to make it work for the first minute or so, and the cylinder would fire if I increased the load, same as your situation.

If I remember correctly, the manual states that a misfire on one cylinder can cause codes to be stored for other cylinders, but the count will be lower, so go after the one with the highest count first. If you have headers, another way to check is to spray a little water on each pipe. The cold one will be easy to detect.

Another thing you might check is compression. Low compression can cause a misfire which goes away once cylinder pressure goes up with increased load.

 

I had my plug wires off once and when I reinstalled them, one didn't fully click on, causing a misfire. It was the strangest thing: the cylinder would misfire quite a few times in a row, filling the exhaust with unburnt fuel. Then POP as it exploded in the exhaust tubing. I was stuck in rush hour gridlock, and my Vette was just farting away like a mother. Not cool. Check the wires for sure!

 

I hope to god its not low compression due to the fact that it did not due this until i got it back from a shop..All the same I will triple check the wires and I know for sure that cylinder #1 had the highest misfire count and Its the one with the new coil pack and new injector now...Im kinda back at square one now...guess its time for a compression check.

 

Make sure you inspect G107(behind the drivers side head). There are two terminals grounded there.......one for each bank......

 

I think I found G107, what is the best way to go about accessing it though...and what size nut or bolt holds it on there? If it was low compression wouldnt I have issues on more then one side of the motor and no predominatly in one cylinder?

 

Mirror and a flashlight work well. You don't have to take it apart, just make sure it's intact. You can also verify a good ground with a DMM, and shake down the harness to see if it breaks continuity. No idea what size hardware. You stated you had misfires on the right bank, just giving one common denominator......not going to get distracted with low compressions issues when it's the whole right side of the engine....

 

Not sure I understand how a misfire which goes away under load, or increased injector pulse width, is electrical.
It may not be the whole right side of the engine. Read the manual regarding misfire counts, and cylinder ID.

 

Ok.

 

May as well check your exhaust pressure at the front O2 sensor holes. Mine had plugged cats and caused misfires on one side. It's simple to check and if it is under 80k miles it's under warranty. should be about 2 psi.

 

car only has 34k on it I got it with 28k. it has long tubes on it with an xpipe to stock mufflers so i dont think i have any clogged exhaust components. im still kind of curious about the compression suggestion and how it could only be giving issues on the 1357 side with cylinder 1 as the dominant problem.

 

I'm definitely no expert on aftermarket parts for Corvettes, My cats were clogged at only 40k miles. If you have cats, I suppose they could plug up, but I don't think I've read of anyone having that problem on aftermarket parts.

If you have cats before the xpipe comes together and only one side is plugged, it will cause that side to run poorly or misfire. The only difference on mine was that I had some sympathy misfires on the other side.

Anyway, its easy to check, so give it a shot and let us know what you find. Check all of the free stuff first