HOLLEY 770 wont idle down.

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tekslk

tekslk

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340 engine with a 770 street avenger wants to run about 2000 rpm. It worked great till today, I eliminated the throttle cable, I backed off adjustment, I even turned fast idle screw out to take everything out of the picture. You can manually grab linkage and force it to slow idle but as soon as you let go it revs back up. I sprayed everything with wd40. It seams to have a bind on it but I cant figure out where, any sugestions or anyone else with this issue?
 
Check the choke fast idle screw.
 
Wow, I wonder why this happened too. Forgive me for what is probably is a stupid question.......But is the return spring still strong?
 
First of all read the post I backed off the fast idle screw. Rick that is a possibility on the spring, this is my buddies 340 duster and when I felt the spring it seams a little flimsy If he brings it up here tomorrow I will change that out for him. Anything else it should all be free but isnt working right at all and did till today.
 
The only place I could think of a bind after running fine for a time, would be a 4 hole gasket that finally swelled enough to grab the primary blades. Again, grasping at straws? :smile:
 
Im grasping too, as far as vacume leak I didnt check that because I can manually force linkage back to where it will idle smooth, if it had a vacume leak wouldnt it do no manner where it idled.
 
Did it backfire, and blow a vacuum plug off?
Is that piece of linkage on the driver's side, going to the secondary, is it closing them all the way?
 
I had one other thought "T". If he's running a "ported" vacuum advance, and if the throttle blades are the culprit and are hanging open a little, that would throw the vac to the dizzy and make the r's spike at idle. If it is ported, you might pull the line and see if the idle comes down with that. It may confirm that the blades are open too far vs. a vacuum leak somewhere?
 
we`ll assume the choke wire is attached and making good connection?
Make sure it`s getting a full 12v.
If not it could be setting on a step giving higher rpm. if that makes sense.
Another words, chokes not completely pulling off.
 
No vacume advance hooked up. As far as I know no backfire. The linkage is the regular carb linkage on drivers side. Vacume secondaries, pretty new carb. Maybe as simple as the spring but it takes a good bid of tugging on linkage to get idle to drop.
 
Well, I guess it could always be a cable issue then? Let us know if you find anything screwy. Good luck, I know you'll get it done. :thumleft:
 
12 volts to the choke, choke blade removed thats why I backed off the fast idle screw to make sure it wasnt hangin up on the plastic cam. I guess its time to sleep on this one maybe the west coast fellows can help.
 
tekslk said:
First of all read the post I backed off the fast idle screw. Rick that is a possibility on the spring, this is my buddies 340 duster and when I felt the spring it seams a little flimsy If he brings it up here tomorrow I will change that out for him. Anything else it should all be free but isnt working right at all and did till today.
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Sorry....I missed that somehow. I'll leave you to it then.
 
Since forcing the throttle closed by hand works, it definitely sounds like it is hanging up somewhere. I had one like that once that I could feel hit a snag right before closing fully. I can't remember if a carb or a TBI, nor what I did to fix it. Maybe add a second spring or a stronger spring.
 
I think it could still be a vaccuum leak.Could you possibly be forcing the throttle blades completely closed and it idles on the leak. Where was the adjustment originally.Maybe you are forcing it closed past the original idle adjustment.
 
just follow the path of linkages and throttle blade travel till you find, or eliminate the carb itself.
It does sound like a vacuum plug came off for whatever reason. (because of the sudden change)
 
Well after all that the choke had a bad ground keeping the fast idle on, easy fixonce we figured it out, makes me feel like a fool. Its always the easy stuff we over look. Thanks everyone.
 
tekslk said:
Well after all that the choke had a bad ground keeping the fast idle on, easy fixonce we figured it out, makes me feel like a fool. Its always the easy stuff we over look. Thanks everyone.
Click to expand...


Well I'll be. Maybe you need to go back and read your own post. lol
 
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