She's BACKFIRING!!! help me....
 

well, a few days ago after a 20 mile drive on the freeway or so, she started popping a little bit, at first only a tiny pop here and there, only when letting off the pedal to shift between 2-3k.

i checked my exhaust, not loose anywhere, everything is tight just as it has been for months....

no loose coil wires or sensors or anything either, and its not throwing any codes...

about 1k ago i installed the champion 1 piece plugs, and last january i installed my full exhaust... and about a month ago i cleaned and reoiled my air filter.

well now she is popping really loud! when holding steady throttle or when barely accelerating mostly, and definately in lower gears when shifting.... and now she feels like shes bucking a little and hesitating during normal driving.... oh and she ran fine at idle when it started, but now seems to be running a little funny, like it has a miss or something...

can i unhook the individual coils one at a time and see how it effects the idle, without getting shocked? i know better than to pull plug wires on a distributor type car cause it will jolt your arse... but never tried it on coil-on-plug

im at a loss here... i did a quick look around and nothing is loose or looks out of place. i even reloaded my tune just to be sure. i definately want to get this figured out myself, and as a last hope i will take it to ford, but i know they will hook her up to a machine, and i dont want to lose my tune over some diagnostics crap ford does...

any help is appreciated guys. i think i will fill her with 93 octane and load that tune, then see if it goes away with fresh gas and a tune, but i doubt it.

usually backfiring is caused by a rich mixture along with fresh oxygen getting into the exhaust and igniting it.....

first suspect is a bad plug or two, not firing right and causing the extra unburnt gas to pop in the exhaust.

anyway thats my take on it all, any help is much appreciated.

-Nate

In the past with older cars, I would always be looking at ignition etc. first.
With these, I might be inclined to look at the MAF sensor and see if re-oiling the filter had gotten it dirty along with cleaning the throttle body.:dunno:

hmmm, just for the info, how would the dirty maf lead to extra gas in the exhaust?

thanks

nate

Hello in my experience with 3 mustangs it might be you firing order is off or the plugs,or not gapped,i have noticed that on my 02,and 97 that ford motorcraft plugs work better,this came from my freind who was a ford mechanic.You might want to check those out,the car will miss fire as well as what you are explaining.

firing order cant be it, plugs were good for the last 1k or so, but i may have a bad plug or two, i have heard horror stories about these plugs....

I would pull the plugs and see if any of them are fouled. It's possible one or more of them are gapped incorrectly and the oil from a possibly over oiled filter is fouling them.

Could be if you over oiled the filter some oil got pulled on to the MAF sensor. Remove it and take a good look at it. Clean it off with some MAF cleaner if it looks even a little oily. Getting oil on the sensor will cause it to send erroneous data to the computer, which will then screw up the air/fuel ratio, although you think this would eventually cause a code to be thrown. Possible you got some bad gas?

its the plugs Ill bet..

well i put some 91 octane in it, then re tuned it and it seems better, but still backfires

i also pulled the coil wires one at a time and you can definately tell a difference at idle when you disconnect them, so that tells me the plugs are firing... i hope

when i get a chance i will take a look at/clean the maf, it probably needs it anyways...

Hey, if you want help troubleshooting just hit me up via PM. We met at flashbacks a few months ago. I know sometimes another set of eyes/ears can help.

The champion plugs are poop. Right after I put mine in I had all kinds of misfires and backfires. I bought a new set of factory plugs for like 50 bucks and all my problems went away

oh man i hope its not the plugs... they are easy enough to change, but i dont wanna go through all that and know i blew 150 on the champions for no reason...

**** those 3 piece plugs!!!!!

I can say with 90% certainty it's the plugs

are you listening? its the plugs...

If you still have them, you can reinstall the original plugs to see if this is the case. The price is free for the test...

yeah just soak them in the carb cleaner first to make sure all the carbon is off before you do.

**** i already threw the old plugs away....

i put in premium and reloaded the tune and it seems to be a little bit better....

This happened on my 06GT.. I drove to SoCal, Knott's, and when I filled up started driving home I noticed it was popping a bit under power going uphill outside of Banning. It got worse the next day after I got home, backfired badley, took it into my dealer and they found that my fuel pump and my plugs were covered in some red gunk, the only thing i put into the tank before I left was some octane booster. Just thought I would throw that in