Justin Brook

Hello,
I have a 07 mustang gt with 140,000 miles on it. I haven't had a problem out of it ever. Well a few weeks ago I was driving home from work and the car started misfiring. I got it home put new plugs in it the next day. The plugs didn't help anything. So I hooked up to a code reader had a cylinder number 6 misfire and a secondary ignition code. I replaced the coil.

The misfire was still very apparent. The car had no power and I could smell nothing but the catts so I put brand new BBKs catted x pipes after all that the car still has a misfire. I has another head so I put it on just for giggles. Still a misfire. I cleat the codes and run it for a minute and I get a cam sensor code a crank sensor code and a misfire in 2, 5, and 7 cylinders. Iv have taken very good care of this car I hate seeing it like this please help.

Glenn

You replaced which head? Did you replace timing gears and chains? Seems like timing may be off. Do a compression test and let us know the results.

houtex

Post the actual codes, they'll help a lot.

Misfire on one cylinder is a fairly specific list of causes. Some of which you've addressed.

Bad spark plug

Bad coil on plug

Bad connector on the harness connector to the COP

Bad wiring issue on that COP's harness.

Fuel delivery, which could be bad injector, or injector wiring issue.

Possible restriction on the intake, causing a 'bad load' into the cylinder.

Possible restriction on the exhaust, causing an inability to get the spent fuel/air out during the cycle.

Possible leak in the intake somewhere for that cylinder, causing a lean.

Bad compression, ring issue(s).

Coolant leaking in the cylinder.

Computer's shot/messed up for that particular cylinder somehow. Bad connector, bad internal wiring, bad component such as a capacitor or relay or whatever... or the code's gone wrong... too many to really list, it all winds up being a computer.

Think that about covers it... maybe...?

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You said you could 'smell the cats'. That means there's raw fuel burning in them. That means the injector for #6 is firing off and sending fuel in the cylinder. Which sort of makes sense if it's not firing at all, but not enough that it should be *smelly*, I'd think. It'd throw some other code if that was the case.

That's a lot of fuel being dumped in the cat, and that pretty much tells me what it probably is. My money's on the bad injector for 6. Wouldn't surprise me at all.

BUT... I'm just a peon takin' a guess after mulling and typing. You might want a dealer scantool and tech involved if you wanna save your baby, your hair, your time, and money spent throwing things at it.

Hope that helps! Good luck!

Glenn

Justin Brook

I replaced the left head, cam, springs, sprocket, and valves. I'll do a compression test right after I test the cam and crank sensor.

Justin Brook

I feel like it's something to do with the timing considering I have misfires in both heads.

houtex

Somehow I missed the 2, 5, and 7 misfires. Probably tunnel vision again. Sorry.

Yeah, timing might be the problem *now*, but on the only #6 before... it probably wasn't.

I do hope you find it.

ford4v429

did you have the lower timing gear/starwheel off? if so, might just need relearned...

unhook battery for a bit, that alone might clear it up, but to 'learn' you need to drive on the highway, and coast down from 60-under 40 in gear,smooth road...it 'maps' that starwheel tooth pattern- it senses minute differences in time tooth-tooth to sense misfire by crank windup.

i had changed a battery, drove several weeks no issues, took highway for first time, coasted down on a bumpy offramp- misfire codes, wouldnt run... unhooking battery cleared it up, did some reading as to why... the bumpy road musta been bouncing the crank enough it mapped the thing out wrong, wouldnt run... did the coastdown again on a smooth road, all was well.