1985 FI 302 idle problem
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From: Howell, nj
1985 FI 302 idle problem
After a slew of problems that I've fixed one by one...the last seems to be the idle. I recently replaced the O2 sensor and FPR. I also put new blugs in and tuned it up. Since then whenever it warms up, the idle goes up and down continuously. It drives fine. Just whenever you stop the truck. Any idea what I can replace on it to make it stop?
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From: Tucson, AZ
in addition to what bob recommends, make sure all the vacuum lines have been reconnected and none are broken...if you still have the plastic lines and have been digging around in there, they are old, brittle and easily broken. cheers, garsten
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From: Howell, nj
I just replaced the MAP sensor on the passenger side firewall and it is still doing it. I pulled of the vaccuum line to the sensor and I do have suction to it. I have also replaced the TPS and the FPR. Any other ideas?
Last edited by turbozeke418; Nov 27, 2005 at 04:25 AM. Reason: additional
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sounds like a similar problem to what I went through the last rebuild opn my 1986 5.0 EFI> Turns out, the gasket between the upper and lower plenum was leaking. Took the upper plenum back off, cleaned up both surfaces, used a little weatherstrip sealer to hold the new gasket in place, and, viola, no more problem. An easy way to tell if this is your problem is to take some spray start fluid to the gasket seam with the truck running., If the motor suddenly revs up while spraying the fluid in a certain spot, you've found your trouble. Make sure that special bolt half way down on the passenger side is properly torques with that special allen wrench looking socket.
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From: Howell, nj
Thanks...I never even thought of that being the problem. After I took off the upper plenum I never even tightened the bolt because I couldn't figure out how to get to it. Now I'll just get the right size allen key. Hopefully that will take care of it?
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you will need a special Ford Plenum socket tool to get to that bolt. Usually any parts store carries them.
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From: Annandale Va
you should replace the iac too... new its about $100 or a cheap one from your local autoparts for about $65 Woth every penny
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From: Eglin AFB
Originally Posted by turbozeke418
Thanks...I never even thought of that being the problem. After I took off the upper plenum I never even tightened the bolt because I couldn't figure out how to get to it. Now I'll just get the right size allen key. Hopefully that will take care of it?
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From: Howell, nj
New problem now...harmonic balancer and crank pulley fell off!!
That fixed the problem. Of course one thing leads to another. I was driving it tonight and the entire harmonic balancer and crank pulley fell right off. I never even touched them before. Ever heard of this happening and what could have caused it. If anyone knows where I can get a new crank pulley I would appreciate it!!!
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