Holley Carb Problems

[Captainfab]

It looks like the choke is completely closed when it is cold. In my opinion, the choke flap should not be completely closed. I still say you just need to adjust the choke. That should solve the issue with the choke flap not opening all the way.

Holley Carburetor Choke Adjustment Tips - YouTube

Installing A Manual Or Electric Choke On A Holley...

[landy]

The flap is almost completely closed when cold. On start-up, it opens slightly to allow for air flow. Truck starts easily when cold, so I don't have issues with the choke blade in the cold position.

I've looked at those videos already, but thanks. Adjustment of the electric choke controls how quickly the choke opens, it doesn't control how far the choke blade opens once engine is warmed up. On my carb, and on similar Holleys I've seen, the choke blade is not completely open at warm up, i.e., less than 90 degrees from horizontal. The choke blade position at complete warm-up is limited by the choke rod that connects the choke blade to the fast idle cam. It physically can't open any futher unless I bend the choke rod. Maybe that's what I need to do and see if it makes any changes in engine operation? Engine runs great when cold or warm, but I'm just wondering if the choke blade position the way Holley designed it and I shouldn't mess with it?

It just idles too high.

[cool68]

you say it is a Street Avenger Carb but, does not look like the one on my motor - see pics above pics of yours. do you have wider view pics of top of engine to post? Holley is a square bore carburetor, are you sure the manifold is a square bore set up? Original Rochester Quadrajet is not a square bore. could be reason secondaries don't work.

[familyfast64]

Here's a pic of my street avenger when I first got the truck. It shows my linkage which you might want to take a close look at, and also my choke wide open... At 90.

If this is even your carb?..

[landy]

Cool68, you're right, it's not a street avenger, but a Holley Street Performer - Traditional, as listed in their online catalog.

The engine has a stock cast iron manifold, so at one time it must've had a Q-jet, which is a spread bore setup. There's an adapter between the carb and the manifold, so I'm assuming it's to adapt the square bore Holley to the spread bore manifold.

I purchased the truck with this carb, which looked fairly new and ran great except for the high idle. I haven't removed the carb to inspect the adapter, but I guess I should do that next.

[Captainfab]

Landy, I just went back and looked at the pics of your carb and noticed something. The rod coming down from the choke flap and the lever it is connected to is above the red fast idle cam. It should be below that red fast idle cam. Take a look at the pic of familyfast64's carb and you will see what I mean. That is likely the cause of your whole issue.

[landy]

Captainfab, that's an excellent observation! I looked at that a couple of weeks ago thinking that maybe the choke rod wasn't installed correctly, but didn't see anything obvious so did nothing further.

However, I think you may be right. I'll look at it more closely.

[cool68]

so, what was the solution to the problem?

[landy]

No solution yet. I've looked at the choke rod and how it attaches to the fast idle cam and it appears to be the factory setup. There's no other place for it to attach. However, as I noted previously, the choke blade at full warmup can't physically open any further than 60 to 70 degrees from horizontal because of the design of the linkage. Perhaps that's how Holley designed it? I suppose I could try and bend the choke rod to get it to open more.

Idle problem is also unresolved. The vacuum secondaries don't appear to be opening, although I've only tried to check it once by tying a wire tie to the plunger rod on the diaphram and accelerating hard. Tie didn't appear to have moved down the rod afterwards.

One of the previous posters had suggested that the secondary butterflys weren't closing completely, thus causing the high idle. I guess the next step is to pull the carb for a look-see.

[GASoline71]

If that choke butterfly never opens all the way... you will always run rich, and then nothing else will work out as well.

For the sake of argument... I have removed the choke from every carbed engine in every car or truck I have owned. Just have to pump the pedal a few times, and feather the throttle a little when ya start it when it's cold.

Gary

[landy]

That's a good idea. I'll disconnect the choke linkage so that the choke blade can be opened completely and see if there's any changes.

[burnin oil]

Originally Posted by GASoline71

If that choke butterfly never opens all the way... you will always run rich, and then nothing else will work out as well.

For the sake of argument... I have removed the choke from every carbed engine in every car or truck I have owned. Just have to pump the pedal a few times, and feather the throttle a little when ya start it when it's cold.

Gary

I agree this works in most areas if the carb is to rich at idle. Once I installed an AFR meter I noticed real quick how rich it is. With everything dialed in like it is supposed to be it wont start without the choke/fast idle below 70*. My idle AFR on a warm motor is still a little rich at 13.4. Just saying.

[GASoline71]

Obviously you won't be able to jump in and set the choke, start it, and walk away. You'll need to sit in the rig and feather the throttle to warm up the rig to any kind of an operating temperature. I've been doing it that way since 1983 when I started wrenching on my own rig I was driving. So I'm used to it.

Chokes suck... period.

Gary