Holley Idle Problem

[Mopar_Mudder]

I have a 3310 750cfm Holley on my 440 that has come up with a idle problem. The thing will not alway (most of the time) idle down where it belongs. It will idle 200-300 rpm high and then all the sudden fall back down. Or if you hold the brakes and drag the motor down with the clutch it will idle down, but sometimes will pick back up 200-300 rpm's again. Any ideas what it might be? It seems like linkage, but I have unhooked it and phicicaly pushed it closed with the same results. I have also checkd for vac leaks the best I could and didn't find any.

[road chicken]

You didn't say if it just started doing it without any other changes, but this possibly could be your motor getting into the distributor mechanical advance. If you've got a weak or broken advance spring this would happen. Not the only possiblity, just my 02c Is your vacuum steady at idle? Does it idle smooth at 700=800 rpm? Either one of those that are a no recheck for the vacuum leak. Otherwise pull the cap off the distributor and see if the rotor returns to the stops by itself, with no play.

Hope this helps, RC

[Mopar_Mudder]

many changes were done at one time and I foget when exactly this started. But the dist has light weight springs in it and is pretty much at full advance at idle. The idle is smooth, just like the carb is stuck open a bit. Vacume is steady also.

[brian phillips]

Hey mudder, That is a taletale sign of a lean idle condition.Solve that and it should idle right down.

[HOLESHOT]

SUGGEST SLOWING THE MECHANICAL ADVANCE DOWN,FULL ADVANCE AT IDLE WILL UTIMATELY DAMAGE THE ENGINE FROM A LEAN CONDITION.YOUR PROBABLY NOT GETTING THE BEST POWER OR MILEAGE LIKE THAT.

[Mopar_Mudder]

I have a air/fuel meter on it so it isn't lean, but I will check some more into that. Think I will pickup a rebuild kit in it and do that first.

[WayneT]

Had this problem on my new 6bbl setup. Found the choke cam was stuck on the adjuster arm. I bent the arm away from the cam and it idled down. Still didn't idle very consistant. I knew from driving it that it was very lean (it surged). Rejetted it and it runs great. Don't know if your carb is new or not but thought I'd throw in a possibilty.