[sbsvt04]

Ok. All of a sudden my svt fell flat on its face at a light. Ever since then it's acting like it's misfiring. The only code is 1131 lack of o2 switch which indicates a bad o2 sensor or a vacuum leak on the intake. I sprayed the intake and all its hoses one at a time and no change in idle. Replaced o2 sensor, no change. Checked spark...2 and 4 will arc from the boot, but 1 and 3 barley. New Ford wires, wondering if it's the coil. But no misfire codes present.

What next? What am I missing?

 

[sailor]

A good Coil?

 

[freemind]

Inspect your coil pigtail for cracked or pulled wires. If there are, replace it.

As sailor said, inspect the coil for any cracks.

Do you own a multimeter?

If so, take a reading of the plug wires, anything over 10K ohms is bad. Return said plug wires.

 

[sailor]

The 1131 code is for maxed out 'lean", correcting for a too rich condition.

Could well be the extra unburnt fuel for it missing.

Not "missing" completely might not set a code right away.

DTC's in the How To stickies are helpful to read.

Freemind covered the other things to check while I referenced that to confirm.

 

[sbsvt04]

No cracked or pulled wires. As for the plug wires, the old ones do the same thing.

The more I got thinking about it, it actually started after I reset the vct cam timing. I had the over advanced code. I adjusted the cam, cleared code, and within a day, this problem

 

[freemind]

Are the plugs gapped correctly?

just because a wire looks good does not mean it is good.

 

[sbsvt04]

Just tested wires...all good. Plugs gapped at.055.
Really thinking coil...

 

[freemind]

Maybe Tom will put his opinion in on the cam subject.

 

[StephenElsbree1986]

I would say coilpack, Did you regap them once pulled? I originally gapped mine to .055 replaced them and was looking at the where gapped at and some even changed to .067. I was amazed. I set my new plugs to .05 the car feels better. Vacuum leaks would have surging rpms. For the car trying to correct the AFR. Our coilpacks are known for going bad.

Also though, check the injectors A clogged injector would not throw a code.

 

[02fordsvt]

My first guess would be the coil. I had it go bad on my SE sedan and it didn't show a code the first few 5 or so miles after it started misfiring. Code did show up later, though.

Had a similar issue with the Svt where it wasn't a misfire but it felt like it. I had a couple other issues but the main culprit was a large crack in the vacuum hose leading to the PCV valve.

 

[limeyrider]

Ok. All of a sudden my svt fell flat on its face at a light. Ever since then it's acting like it's misfiring. The only code is 1131 lack of o2 switch which indicates a bad o2 sensor or a vacuum leak on the intake. I sprayed the intake and all its hoses one at a time and no change in idle. Replaced o2 sensor, no change. Checked spark...2 and 4 will arc from the boot, but 1 and 3 barley. New Ford wires, wondering if it's the coil. But no misfire codes present.

What next? What am I missing?

"...at a light..."

Idling?
Do the 'plugs, wires, coil, coil pigtail' checks

Do you also have intermittent 'hunting for idle' when you're off throttle?

You might also want to check the IAC valve and clean it with some throttle body cleaner - keeping the electronic end up so you don't flood it. ALSO, the PCV valve grommet and rubber elbow are right next to the header so they get cooked and they will harden, crack and lose seal, allowing a vacuum leak. Your PCV valve should be clean and stay shut even upside-down.

 

[sbsvt04]

Actually, what it ended up being was my vct gear.

 

[limeyrider]

Actually, what it ended up being was my vct gear.

The oil valve/solenoid or the cam pulley?

 

[limeyrider]

Had a similar issue with the Svt where it wasn't a misfire but it felt like it. I had a couple other issues but the main culprit was a large crack in the vacuum hose leading to the PCV valve.

Mine was the PCV valve elbow hose and grommet.