misfireing above 4500 rpm

[kramer2125]

So get this, above 4500 rpm my motor loses power and backfires. I have to let off the gas and allow the trans to upshift, and then accelerate more. Its like granny shifting the auto and it sux. So i replaced the plugs and wires and coil packs. Its still doing it!
Is it possible that its the wires again?

I might need to get Hi temp sheathing. Will the high temp sheathing protect the wire if its touching the header head shield or the header itself?

Would anything other than plugs, wires, coils cause the backfiring and loss of power?

I've replaced my fuel filter 200 miles ago. Its not that. My bird has 38k miles, so i doubt its the cat.

Your thoughts?

[FunkZ]

No SES?

[kramer2125]

Left that detail out, yes, ses. its throwing a random cylinder misfire code as well.

[Fredless]

Is it just me or does there seem to be a large amount of misfiring problems being posted lately?

Mine has a WOT knock problem that started with my #3 wire becoming slowly fubar'd.

higher octane gas doesn't fix it either, but it doesn't hurt performance that I can tell.

[kahouna23]

Just a little info for ya...check the camaroz28.com forum under the V6 section. They posted a sticky thread about the "mysteries of misfires" dealing with the V6. It's been an ongoing problem with just about EVERY V6 owner. There's a LOOOOOOONNNNNGGG list of possibilities that could contribute to a lack of power. My car had this problem about 30,000 miles ago, which ended up being the way the plug wires were routed. I had it fixed at the service department and until recently, no misfire. Now it's back. So, does your car run fine when it's cold on initial startup, and then misfire when it's warmed up? If so, chances are it's the routing of the wires, plugs, cat, or even the O2 sensors. When you have a misfire problem and continue to drive it, it has a tendancy to foul the O2 sensors as well...this in turn causes a premature shelling of the catalytic converter due to the unburned fuel collecting there. Not trying to scare you but it's basically a "hit or miss" situation trying to find a misfire problem. Let me guess...you have a P-300 SES code? Just be prepared to throw parts at it until it eventually fixes it. Seriously though, check out the Z28 forum for more info.

[Turbo V6 Camaro]

many many times high RPM missfire was tracked down to the ICM going out.........

when it is dark pop your hood and star the car, see if the sprak is arching somwere in the bay, you will see it if it is.

[93camaro_zzz]

Originally posted by viper04af:
many many times high RPM missfire was tracked down to the ICM going out.........

when it is dark pop your hood and star the car, see if the sprak is arching somwere in the bay, you will see it if it is.

This is what I would do. Also, I dont know if you have access to one, but a scanner can tell the world about what is wrong with car repairs. Sometimes these weird codes are something simple like plug routing, etc. Also, you can see what EVERY sensor on the car is putting out in voltage and compare it to a guide, and see what the problem was. Goodl uck with it. ;)