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1999 Ford Mustang

Okay I am having a problem that has plagues me for about 80000 miles and nobody can give me a clue including Ford. When my engine is warm and stuck at a standstill in idle it misses horribly like it is about to die. Occasionally at lights the tach jumps from 800 to a grand and then back down to 800. I have recently replaced the plugs, pcv valve, and fuel filter. It is also particularly bad after I park it for an hour or so come back and start it and back up. I have run Seafoam through the gas and also directly through the manifold. Any help is gratly appreciated. Thanks,

Ned

Reply to
Redstang66
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IAC motor..... Look here:

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Could also be the EGR valve not seating correctly. Remove it and clean the pintel (carefully!! do NOT spray carb cleaner all over it because you will ruin the diaphragm).

Also clean the intake ports under the EGR valve. You CAN spray carb cleaner in there.

One last thing, ditch the SeaFoam...

Reply to
Stefani Bowers

Reply to
Redstang66

If you use a good brand of gasoline you shouldn't have to because the top tier gasoline has additives in it already. However, a bottle of Techron or STP Fuel Injector Cleaner (the black bottle)once in a while won't harm anything.

If you have a severe carbon problem, on an older not well maintained motor a treatment with GM Top Engine Cleaner will work wonders. Be sure to follow the instructions TO THE LETTER and understand you will generate smoke out the tailpipe like you have never seen. This is normal.

Make sure to change your oil and filter after the treatment.

This is a last resort BTW.

Ford may have their own version of the stuff. I don't know.

Reply to
Stefani Bowers

Thanks and I cleaned the Throttle body and IAC motor and it is idling a ton better almost like new. Thanks so much for the help

Stefani Bowers wrote:

Reply to
Redstang66

Reply to
Redstang66

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