misfire troubleshooting cont'd

[mike h]

im going to have the plugs and wires replaced on wednesday. but until then i thought i would try to figure some stuff out.

the car misfires when: at a stop, accelerating
the car doesnt miss when: i am coasting

when you are coasting is there something different with the firing of the cylenders to make it not miss? im confised b/c it does it when im at a stoplight at idle but not when i am coasting at any speed.

[firebird4u99]

It actually may still be misfireing while coasting it's just harder to hear it due to road noise. The exact same thing happened to mine but once I hooked up the diagnostics scanner I could see that it was misfireing even while coasting.

[firebird4u99]

And by the way changing the plugs and wires fixed the problem and made it run much healthier which in turn made gas mileage go way up.

[mike h]

well i know when it misfires, the RPM's jump 500 and up to 1000 each time. sometimes it doesnt happen for a long time other times it is so bad i can hardly drive.

[firebird4u99]

Yeah this sounds exactly like what my car was doing before I got the plugs and wired replaced. Make sure your mechanic uses the stock AC Delco plugs and AC Delco wires unless you have nitrous or a blower.

[kahouna23]

The main reason you can't tell it's misfiring when you're coasting is because you're not putting any load on the engine, but as soon as you give it fuel.........misfire city!!

PLUGS AND WIRES!!

If you're still under warranty, take advantage of it. Otherwise, it's about a 1 hour job...2 if it's your first time. DON'T TAKE IT SOMEWHERE TO HAVE IT DONE....do it yourself, unless you have absolutely no mechanical ability. It's really easy though. If you can color and stay within the lines......you're in there like swimwear. Heck...if you can't do it, bring it to Vacaville and I'll do it for you...only cost you a case of Corona ;)

[red01maro]

I had the same problem a while back on my 96 firebird, it ended up being a bad coil pack. Recently Im having the same problem again, this time I found a bad fuel injector, bought a new one and I think the new one is bad, not positive though, still fighting with it. Give those items a thought if the plugs and wires dont fix the problem.