1989 f150 revving problems

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Feb 22, 2003 | 05:14 PM

coolgreen

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Joined: Feb 2003

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From: Newmarket, Ontario, Canad

1989 f150 revving problems

my '89 f150 4x4, 302 5-speed has a wierd revving problem. When I take my foot off the gas pedal to shift gears it revs up at least 500 RPM, then slowly goes back to normal.

I replaced the intake air control valve, and although it seems to run better the revving problems persists. I could probably keep replacing parts until my bank account it empty before I figure this out.

I took it into a local shop and the mechanic disconnected the battery for a half hour and cleaned out the intake, which wasn't very dirty.

He said it may go back to normal in a day or two. This sounds like crap to me. Also a waste of $75.

He said if it was the throttle positioning (whatever) there would be a dead spot, so it shouldn't be the problem.

I don't think anyone can figure out why this thing is revving.

I have to go out plowing tonight, and it's going to be a pain in the butt to have this thing revving like that.

Is my only alternative to take it to a Ford dealer and pay HUGE bucks?

Thanks.

Feb 22, 2003 | 09:03 PM

torquey89ford

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Joined: Feb 2003

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From: Portage, MI

1989 f150 revving problems

You sure the throttle just isnt stickin a little? That or what the tech said, have your throttle position sensor checked.

Feb 25, 2003 | 01:15 AM

Yogi2899

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Joined: Feb 2003

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1989 f150 revving problems

I just bought a used 1989 F-350 5 Spd Manual 5.8L 4x4 with the revving problem. The person I bought it from said it was a bad "throttle position sensor". He never bothered to change it because it did not bother him. I would like to correct the problem. Is it an expensive part? Can it easily be changed? Any help would be greatly appreciated.

Feb 25, 2003 | 01:24 AM

Chas1234

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Joined: Dec 2002

Posts: 925

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From: Quaker Hill ,CT U.S.A.

1989 f150 revving problems

the throttle postion sensor is easy to do on these trucks ..you need to buy a new throttle body gaskek (yes you get to remove the body) you really should get a haynes manual..but be fore you remove any of these parts pull the codes ..that maunal will show you the proper way to set the tsp so that the engine doesnt idle to high ..

Feb 26, 2003 | 04:03 PM

glazer1972

5th Wheeling

Joined: Mar 2002

Posts: 47

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From: Lufkin, TX

1989 f150 revving problems

My 93 5.8L kept doing this. Everbody said electrical, sensor, computer, IAC valve, TPS, yada yada yada. I changed a bunch of crap and checked a bunch of crap to no avail. I took off the Throttle Body and manually operated the butterflys while holding it close to my ear and lo and behold the was some slack on the shaft that was allowing air past the butterflys. I ordered a new throttle body from Ford and it included the TPS and IAC. (some of the parts I had already changed) Installed the new throttle body and it hasn't done it since.

Hope this helps!

Feb 26, 2003 | 08:09 PM

coolgreen

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Joined: Feb 2003

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From: Newmarket, Ontario, Canad

1989 f150 revving problems

Thanks for all the replies. Like my mechanic said (although I didn't believe it at the time) the idle seems to have settled down a little since resetting the computer and installing the IAC. It's still not perfect, but it's a lot better than it was.

I'm hoping it will go back to normal as I drive it more.