Problem has me stumped. Bad miss once car is warmed up. Scan tool says P307...have changed cyl 7 plug and coil boot assy. Problem always comes back to cyl 7. Think my next step is injector or computer? Is there some other diagnostic isolation I am missing? Ruled out the engine valves or piston because it does not act up until its moving down the road and warm. Any suggestions would be appreciated............jb
98 Merc GM 4.6L Bad miss
Jan 21, 2007
2 Replies
P307...have changed
next step is
Ruled out the engine
warm. Any suggestions
Sticking valve.
More common on the Triton DOHC, but a likely culprit after warm-up.
Maybe a treatment w/ Marvel Mystery Oil & a change to Mobil 1?
If you need an emissions inspection, you're in trouble, otherwise it's probably just a live-with situation on an almost 10-year-old car.
Rob
P307...have changed
next step is
Ruled out the engine
warm. Any suggestions
Check very close for any moisture in and around the plug well. Any water leaks that dampen the wire but not enough to see without looking real close.
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