Holley Carb Question

[knish71]

Hi all, I'm new to this forum as I just recently purchased a 1971 LT-1. I love the car (even though I haven't driven the car as yet because of the weather in Toronto).

My question/problem is with the fast idle. I have the original list-4801-a holley carb and when I start the car, the fast idle is set that the car is revving at 3200 rpm. It takes a good 5 minutes to be able to kick it down to 2200 rpm, then another few minutes and it kicks down to a 900 rpm idle.

How/where can I adjust the fast idle so I don't wreck the motor? Also, what should that fast idle be?

Thanks for any and all info.

Robert

Toronto, Canada

 

[Mike Baskette]

Wecome Robert, I have a 71' LT coupe. I have come to realize that sometimes it is best to take my cars to a professional tuner. The fast idle should be controled just by tapping the gas pedal. If there is no control by this action then there are other issues to be addressed. The mechanic tells me it's is not rocket science......I guess my rocket would have never got off the ground. The LT was not running well when I took ownership as I smelled alot of unburned fuel (check my other posts). The valves were so far out of adjustment that it was equal to an open door with the carb just pouring gas through them. Sorry....got carried away. Trouble is, if you adjust the fast idle at its high point the motor won't run at normal operating temp. So........in sumation, I have not helped you a darn bit.

 

[knish71]

Thanks Mike. I agree that a pro will do a much better job than I can ever, but would like to turn it down a bit until I can get it to them. Do you start your car during the winter? What is your fast idle rpm? I'd like a reference to see how out of whack mine is. I live in a pretty cold climate in Toronto during the winter. Where do you live?

 

[Mike Baskette]

Winter? Hmmmmmmmmm, San Diego. We are quite fortunate as we drive our collectors in this area year round. Now on the serious issues, I think when I start the car it is around 2500 but I quickly bring it down to 1500. Idle is 750 to 800, I can't remember. Hope that helps. Hey, post a pic of your car.

 

[71VERT]

I live in Buffalo and have my fast idle set at 1600 RPM, although not the original 4801 yours should be around the same. Just turn it back until you get to 1500-1700 . It will kick down much better from there.


Jerry

 

[knish71]

Thanks Jerry and Mike. Can this adjustment be made hile the engine is running? I've read that the adjusting screw is only accessable when in full throtle. I was told to back the screw out with the engine off and to open the throttle full, then back the screw off. Is this true?

 

[71VERT]

Well you can do it with the car running you just need the right screwdriver , I have done it both ways, It is easier to just shut the car off and hold the throttle open, and use a wrench to adjust the screw, or you can try with the car running with a screwdriver try to turn the screw its not as easy though but it can be done.Jerry

 

[knish71]

Thanks Jerry, gonna give it a try tomorrow. Wish me luck.

 

[knish71]

Jerry, one last question. How sensative is the adjusting screw? I have to take the fast idle down about 1600 rpm. how may turns do you thing it will take?

 

[71VERT]

I would go at least 1 full turn to start then check it from there.

 

[knish71]

Thanks Jerry.

 

[knish71]

Well, I spent about 30 minutes this morning with a trouble light and pictures found on the interenet of this elusive fast idle screw. For the life of me, I can't find it. What a loser!!!! If all else fails, I'll have to bring it to a mechanic when the weather gets better. I was going to anyway, just to have a pro check it out to see if the car requires anything.

 

[71VERT]

Where are you looking for it? stand on the passenger side of the car, open up the throttle all the way and look under your choke on the passenger side and you will see the screw.

 

[knish71]

That's exactly where I was looking. I saw nothing that resembles and adjusting screw. Just different mounting screws for the choke and other attachments.

 

[71VERT]

I think I figured out your problem, you dont have a screw on a 4801, may manual says to bend the fast idle lever to adjust. It shows putting a screwdriver in a slot on the lever and bending it to obtain the correct fast idle speed when its positioned on the top step of the fast idle cam. If you have a fax I can make a copy and fax it.

 

[71VERT]

Let me know your email and I will send you a picture I scanned.

 

[knish71]

71VERT,

It's funny you mentioned that. I also read the same thing, but I wrote to Holley tech support, and even they said there should be an adjusting screw. I have to beleive that you are correct and I don't hink that I'm skilled enough to even try this. With my luck, I'll adjust the wrong way or break it. Thanks for the offer, but I don't have a fax. If I can bother you once more? Would it be possible to scan it and email it to me at rabooey@hotmail.com? Thanks

 

[knish71]

I want to thank all of you who took the time to respond to my question. I especially want to extend an extra thanks to Jerry in Buffalo (my neighbor to the south). I twisted the tang as you explained and it was exactly what it needed. The fast idle is now set at 1600 rpm and run sweet. Thanks once again.

P.S., Jerry, my wife and I often visit Buffalo to shop, one day I'd like to drop by and thank you in person and check out your LT-1. See you soon.

Robert

 

[knish71]

Mike, it took a while, but here is a pic of my car just moments after it rooled off the transport.

Winter? Hmmmmmmmmm, San Diego. We are quite fortunate as we drive our collectors in this area year round. Now on the serious issues, I think when I start the car it is around 2500 but I quickly bring it down to 1500. Idle is 750 to 800, I can't remember. Hope that helps. Hey, post a pic of your car.