misfiring through out speed range

slocum55 · #1 (**permalink**) 03-28-2009, 02:54 AM

can the knock sensor cause the car to misfire through out the speed range . car is missing or hesetating no mil light just ks code .

sergey85 · #2 (**permalink**) 03-29-2009, 03:01 AM

naw i dont believe the knock sensor would cause that. have u tried switching the coils around to see if u can pin point the one thats giving u trouble. what the milage on your car? a misfire is usually cause by bad injectors, coils or spark plugs

slocum55 · #3 (**permalink**) 03-29-2009, 03:33 PM

Car has 141000 on the speedo . the check engine light is off would it be on with misfiring and rough running

sergey85 · #4 (**permalink**) 03-29-2009, 08:24 PM

it can but sometime it doesnt. i would scan it anyways autozone they do it for free. like stated above it can either be sparks(shouldnt bve much just get regualr ngk platnium spark plugs), leaky injectors or a bad coil. so if hasnt had a tune up i would start with saprks and look for some coils. with coils i believe u can swap them around to see if u can pin point the problem. with the car running try unplugging the coil if it gets worse than its not the problem if it just runs the same than that cylinde rmay be the culprit.

dudewithacar · #5 (**permalink**) 04-15-2009, 02:54 AM

You ever figure out what your issue was?

I've been having the same issue, but it doesn't do it all the time. I bought a complete set of used coils off eBay and replaced them all, and it seemed to help for about a day then it started acting up again. Seems to only have an issue when the engine is under load, i.e. in gear and accelerating. I replaced the spark plugs not too long ago. Had the engine codes checked and its not throwing one that has anything to do with this. But like I said its not all the time, only does it sometimes, and it doesn't run rough at idle, although sometimes I can feel it hiccup like its misfiring. My buddy works at a Dodge dealership in Austin and I'm gonna take it in to see if they can diagnose it, they are having a special right now for $30 to diagnose, so at least maybe they can narrow it down to which injector if it is that, or I'm suspecting maybe one of the used coils I installed was bad too. guess I'll find out soon, hopefully.