Slow return to idle
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Slow return to idle
I have been searching all over the internet. I have a 1992 F350 460 4x4 manual, Starts and drives fine cold or warm. But while driving and coming to a stop light/sign the idle sits at 1500rpm, it does drop after sitting for a while at a long stop light. I have checked for vacumm leaks and cleaned the IAC and still does it, what else could be causing it? I do have ABS light that goes off and on. Not sure if that is causing part of the issue or not.
Logistics Pro
Joined: Dec 2003
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From: Foothills of NC
Do you hear a hissing from behind the gauge cluster when pushing the brake pedal with the engine running? You could be losing vacuum from the brake booster when stopping, and after it builds back up the engine idles back down. The seal around the brake rod gets old and worn, and will leak when the brake pedal is pushed.
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Update, so no hissing from under the dash, checked cable and throttle all seems ok, I unplugged the IAC and idle dropped right down. I assume I might have a bad IAC. I will add I don't notice it doing it when the engine is cold-cooler
FTE Legend
Joined: Jun 2006
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From: Ottawa, Ontario
The IAC usually only does what it is told to do so the real problem could be elsewhere, have you puled codes?
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Ok checked for codes tonight. 1 flashed 3 times then got a 34 and 95. I know my front tank pump is out and tank needs cleaned and pump replaced if thats even what the 95 means. The 34 not sure what that could be
the 3 flashes of one could be 12 not sure.
the 3 flashes of one could be 12 not sure.
FTE Legend
Joined: Jun 2006
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From: Ottawa, Ontario
34 is for EGR fault, depending what test it was for it could be indicating a position sensor fault or just an instruction you didn't follow. Either way an EGR fault won't produce your problem unless fresh air is getting into the system and the valve is hanging open when it shouldn't.
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So your saying just blocking off the EGR will cause other codes besides the 34? From what I have read it causes a CEL to come on. If other codes pop up but dont turn light on it would be worth it to have the plug that way my light is not on all the time.
Logistics Pro
Joined: Dec 2003
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From: Foothills of NC
I have a piece of sheet metal cut to the size of the gasket sandwiched between my EGR and manifold. Been like that for at least 15 years. I have no idea what kind of codes I have. As long as the truck is running to suit me I don't check, but with the way I have my engine set up, I would suspect a few.
Black electrical tape carefully placed can eliminate those pesky anti-lock lights..lol
Black electrical tape carefully placed can eliminate those pesky anti-lock lights..lol