idle probs
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New User
Joined: Aug 2004
Posts: 20
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idle probs
O.K. So if idle mixture only affects the idle, when you turn them out, sould I be getting more or less fuel during idle. Its a holley 4180, I have got it on 86 f250 with a 460. I have a real rough idle, seems like it is starving for fuel, but only at idle. I am in Denver with elev. of 5,280 so if any one has an idea how far I should back them out as a starting point, I would appreciate it more than you know. Thank You,
James
James
Elder User
Joined: Oct 2004
Posts: 984
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From: Winnipeg, Manitoba
Best thing to do is to get a vacuum gauge, hook it up to an un-used vacuum port on the intake or near the carb, and then adjust each mixture screw until highest vacuum is attained, then back them off slightly so as not to run to lean. Turning out will generally raise the vacuum. I tend to turn both screws all the way in, and then back them out 2.5 turns each, start the truck, and then adjust from there. This should be done with the truck at full operating temperature. After this, you'll likely have to adjust the idle as well.
Freshman User
Joined: Mar 2004
Posts: 28
Likes: 0
From: 180 miles NE of Phoenix 6
one thing you might want to look at is the idle air bleed restriction.. A lot of people over look this.. I have found that this can help a lot to staighten out the idle.. I use carburetor cleaner to clean them, but wear glasses so you don't get it in your eyes should it come back at you..
Thrillseeker
Thrillseeker
Freshman User
Joined: Mar 2004
Posts: 28
Likes: 0
From: 180 miles NE of Phoenix 6
It is obvious that I must not know how this site works.. jriley301 ask why his truck had a rough idle.. My self and at least one other answered him in a term that did not include the words idle screw.. I also am wondering if that is the reason my answer and at least one other had the term off scale next to it.. To those who are not sure there is more reasons than just the idle screw that will cause rough idle.. Both the answer I gave and the one that fornaroj gave will cause rough idle but yet he and I have the term off scale next to our answer.. Will some one please explain the reason for the term off scale.
Thanks
The Thrillseeker
Thanks
The Thrillseeker
