high revs
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Joined: Dec 2002
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high revs
I have a '93 and '95. w/351/auto. both are 'idling' at 1800-2200 rpm. I bought the '95 that way, but the '93 started after sitting for a couple months. They run fine, but really slam into drive when I start up in the morning, and braking is tougher.
I've actually put rubber caps over the throttle bodies and the things still run. If I unplug the control on the throttle body, they drop to 700 rpm, but drive like crap.
I'm assuming vacuum leaks, but can't find a thing. Vacuum lines all look good.
Do these have a problem with head gaskets?
I've actually put rubber caps over the throttle bodies and the things still run. If I unplug the control on the throttle body, they drop to 700 rpm, but drive like crap.
I'm assuming vacuum leaks, but can't find a thing. Vacuum lines all look good.
Do these have a problem with head gaskets?
Posting Guru
Joined: Jun 1999
Posts: 1,525
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Clean the throttle plates and bores as well......solvent and toothbrush works fine.....when you restart the motor...it usually acts funny for a couple of blips of the throttle. If that don't cure it...you have a engine coolant temp sensor out of parameter...not broken..just not right.
Phillip
Phillip
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Joined: Mar 2002
Posts: 19,402
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From: Bonita Springs FL
A bad ECT will show up in a code scan, and won't cause that kind of behavior anyway.
You have a vacuum leak somewhere. The 351 likes to leak around the intake gasket. Sometimes it will actually suck the gasket in. If you unplug the IAC and the truck doesn't die, then something is feeding the engine air. Without the IAC, the engine doesn't have enough air to run.
I would take the TB off, clean it, check the TPS while you're at it, and clean the IAC. Then see where you're at. If it's still too high, I would check for leaks with an unlit propane torch.
You have a vacuum leak somewhere. The 351 likes to leak around the intake gasket. Sometimes it will actually suck the gasket in. If you unplug the IAC and the truck doesn't die, then something is feeding the engine air. Without the IAC, the engine doesn't have enough air to run.
I would take the TB off, clean it, check the TPS while you're at it, and clean the IAC. Then see where you're at. If it's still too high, I would check for leaks with an unlit propane torch.
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