High Idle

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Sep 24, 2000 | 07:39 PM

Raul

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From: Northern Virginia

High Idle

81 F-100 I6, Carter YFA 1V w/o feedback.

For many months I have put up with a high idle because it was so erratic that if I tried to turn it down it would die. Today I found a leak at my body frange gasket, pulled the carb off, tightened it up ('cause I couldn't find a new one anywhere). Reinstalled carb and it idles very smoothly, vacuum gauge no longer has any movement. Steady 22.

But my high idle is still here. Supposed to idle at 600, but I can't get below 900 when warm. Dashpot backed off, curb idle backed off, high idle screw missing (I gotta get one somewhere) and that's as slow as it will go.

Is there something I can adjust (timing??) or bend that will get my idle down. It is so smooth I think it will run fine at 600.

Any ideas on how to get there greatly appreciated.

Thanks
Raul

Sep 24, 2000 | 11:05 PM

PAUL_2

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High Idle

Its possible you have another vacuum leak ? Check around the intake for any sealing problems .

Sep 25, 2000 | 09:14 PM

Raul

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From: Northern Virginia

High Idle

Thanks, Paul. Darn, it runs so much smoother now that I thought I had it. On your advice I will keep looking. Bear with me a little longer---

I will check (weekend) intake for bolt tightness. Couple of questions: My Chiltons manual shows one bolt/nut tightening sequence, my Ford shop manual and Haynes show another. Guess I'll go along with the Ford. Sound right? So, should I try to tighten up bolts and nuts as they are, or should I take one off at a time (in proper sequence), lubricate threads, and tighten to specs. One of the books I looked at after your message did indicate "intake manifold bolts loosen over time, you need to re-torque them" I hope that is it.

Thanks for the help. Raul

Sep 25, 2000 | 10:36 PM

PAUL_2

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High Idle

Id go along with the Ford torque & sequence . What I have used to locate vacuum leaks is a mechanics stethescope with the metal probe removed & a length of 1/4 copper pipe used in its place . Any vacuum leaks become very audible . Be careful with it , banging it on anything is extremely loud . If you retorque the intake bolts , depending on what it is made of ; The newer engines use aluminum intakes which can break if over tightened . Also the problem may still be with the carb ? Its hard to say for sure w/o seeing whats going on .

Sep 26, 2000 | 02:23 AM

jopey

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Joined: Sep 2000

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From: Bay area

High Idle

I have a complete motor from a 85 bronco that was the I6.

email me if you want anything from it. we can work something out.

Sep 26, 2000 | 07:53 AM

Raul

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Joined: Apr 2000

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From: Northern Virginia

High Idle

Thanks, will keep it in mind. However, motor only has 78K miles on it, and other than a high idle (and lost high-idle screw) everything is OK. I think with the help of folks on this site I will get this thing purring.

Thanks for offer.
Thanks for advice, Paul.
Raul