missing and backfiring

Need some thoughts.The 07 gt is running very rough.When COLD it backfires,pops,and bucks.After 2-3 miles and engine is up to temp,it seems to run ok.Vacuum leak,bad gas,or any other ideas.The car ran fine when it went to the ford dealer.The supercharger has been off to fix a coolant leak.It's going back next week unless i can figure it out this weekend.Thanks.The car sounds fine in the garage,seems to be worst when under a load.

Mass Air meter may need a bit of cleaning....I would also check the Throttle Positioning sensor...and the Throttle body. Wonder if your spark plugs could also have some effect? But you said its running fine when warm....hmmmmm this is a good one

Bad gas does come to mind as well Tony. Mine and justins were bucking and backfiring when we got a batch with water in it.

We tried to get on the car a bit and the check engine light would come one. NO BUENO for us

Tony mine is a little rough like that when it's cold. I always let it run for about 60 seconds before I drive when I first start up. Bucking and so forth. After it's got some heat in the o2 sensors it smooths out fine. Have you got a check engine light?

ahhh good call David...BUT if it persists more than just on initial startup...you may also want to check to see if the O2 Sensors are still good.

If the idiot light is on there is an issue for sure. If not. Could just be cold natured.

DBLDARE wrote:If the idiot light is on there is an issue for sure. If not. Could just be cold natured.

Could try to pull codes with the XCAL...even if there isnt a Check Engine light....to see if there is an occurring issue that is registering?

tony, mine is very cold natured. i have to let it warm up to operating temp or it does the same thing. it did it after the cam install and only got worse after the procharger went on. when it is up to temp it runs fine

Yep. Cold natured for sure!

Doc good to hear from ya.

When i get home,i will let it warm up before i put it on the road.No codes so far.It was running perfect when they got the car.I feel like it is sucking air at the base of the supercharger,and when it warms up it seals off.Will try and run the fuel out of the tank with a run to okc.and back and put in fresh fuel.Using the x-cal to pull codes is a good check but i don't know how.

spray the base of it with carb spray before it warms up then. if the idle surges up then you have a leak there.

also could be a blown headgasket, thats what mine did when I blew it. would seal when it got warmed up.

Plug her in...scroll till it says vehicle information (I THINK) then choose DTC codes...should show you any if you have them

Will try all of the above,keep them coming boys.

It's the hood flame. That's all.

You may be on to something.The mech took it off when he took it for a test drive last week.I'll put it back on tonight.

+1 on the hood mohawk!!

Fire back on hood,Bang car runs fine.Fixed it's self

carcrazy53 wrote:Fire back on hood,Bang car runs fine.Fixed it's self

lol but that sucks i cant have a mohawk to make mine run better just now keeping them straight.

carcrazy53 wrote:Fire back on hood,Bang car runs fine.Fixed it's self

Thats what Im talking about!!! Nice Tony!

I knew it.

I had washed the motor and believe water got on the coils or some other electrical componet.I opened every connection i could find,blew them out with air and reconnected with dielelectric grease.I then installed the fire back on the hood.BAM all is good.

so it was your fire blanket the whole time/? ahhh that stinks atlest you got it fixed

Hard to imagine anything being "Cold nature" in 100+ heat! :)

Tony...any update on your cold start issues?

Posted above.Water

carcrazy53 wrote:I had washed the motor and believe water got on the coils or some other electrical componet.I opened every connection i could find,blew them out with air and reconnected with dielelectric grease.I then installed the fire back on the hood.BAM all is good.

Oops must have missed the explaination...Sorry about that Tony

Now we just have to get the oil leak fixed.This will be the 4th time.I still believe crank case pressure is pushing oil out.They have replaced the rear main,rear main housing,oil pan gasket.They will open it up again in 2 weeks.If not fixed this next go round,it's gone.They are thinking new block.I'm thinking 5.4 VISTA BLUE OF COURSE.