Getting a misfire, can it be mechanical?

pHEnomIC · #1 (**permalink**) 03-20-2005, 01:23 AM

I get a misfire every so often on my 97z28. I was wondering if the ses comes on when there is one single misfire or does there have to be a lot of them in order?

The light usually goes out on its own after a little bit of driving. I have new spark plugs and wires.

I had some problems with my spark plugs coming loose before but i cleaned the threads and got em in snug and the misfires went away.

Is there any way it could be a mechanical problem instead of ignition/electrical?

One of the wires has a small nick in the insulation it but i put in some jbweld and wrapped with electrical tape so i don't think that will cause a problem. I will replace the wire later, dont feel like rerunning wires.

Any other ideas?

BTW, I noticed it happens most often when i am idleing for a long time, hit a big bump or slam the brakes. Everything seems to be tight electric wise though.

ta12sec · #2 (**permalink**) 03-20-2005, 03:38 AM

Im pretty sure all obd2 cars have to have th eoccurence at least twice in 2 20 minute cycles unless it emisisoons related to set an ses light. Could be lots of things buit jbweld on a ign cable would be a good start if jb wled is (idont know if it is) conductive it would transmits to ground and you would have a dead miss

#3 (**permalink**) 03-20-2005, 10:03 AM

I was thinking the same about the JBWeld.

ta12sec · #4 (**permalink**) 03-20-2005, 10:43 AM

of course it can be mechanical as well, bent valves, sticky valves bent pushrods broken springs can cause misfries too

pHEnomIC · #5 (**permalink**) 03-20-2005, 01:17 PM

JB weld is non conductive and has a melting point over 600 so it should be good. I already put it on there and didnt have a problem for a while. I also wrapped it with electrical tape and put a plastic thing over it. I watched it closesly and didnt see or hear it arc.

Correct me if im wrong but can you hear a misfire? When i got them a lot i could hear at idle the car make a different sound every few fires. Like duh duh duh duh duh duh poo duh duh duh duh. Strange thing is I got the ses but i didnt hear that this time.

#6 (**permalink**) 03-20-2005, 01:26 PM

You should hear it. Mine did it not too long ago (code 0300, multiple misfire) and yes it sounds like its running on about 6 cyl, and will "pop" out the exhaust every now and again. Plus if you put it in gear...................wholly crap you think that the engine is gonna shake outta the f'n car!

I think mine was caused from putting stabil in the fulel for winter storage and not taking my tune back to stock on the pcm. Cause after I put it back to stock the misfire went bu-bye! :smt045

WishIHadACamaro · #7 (**permalink**) 03-20-2005, 08:01 PM

I had my car misfire on two seperate occasions.

Once was when my #6 Coil Pack Decided to go bad. It was horrible but still driveable. SES Light came on for this one. Fixed after the pack was replaced.

The other time was when it was rediculously cold outside. I started it and it damned near had a hard attack. It shook violently when in gear. Went away after it warmed up. Funny thing is that the SES light didnt come on.

reckless01 · #8 (**permalink**) 10-02-2005, 09:55 PM

Could be a plug, Timing....