This is sooo strange. I set the Holley electric choke about 3/4 closed and fired the engine up, cold. Before starting it I pumped it to the floor once and started it with no trottle. It ran great for about 15 seconds at 1200 RPM, then leaned out and dropped to 500 RPM, almost stalling, then came back to 1200 where the choke idle point is set. The next day I did the test again with the car cold. It did the exact same thing except it died. I started it again and it ran right up to the choke idle setting and had no problem. It does "pop" (not backfire) every 15 seconds or so until it warms up. That would indicate a lean condition. The choke butterfly is fully open after about 45 seconds. I tried setting it for more choke but that does not help the lean condition at 20 seconds. It's like it starves out for a couple seconds and then comes back.

This is making me crazy. I should be able to start it once and not have it lean out and die after 15 seconds...and it only does it once. The power valve is OK and I have 12 " of Vacuum. The floats are set perfectly and I have 70 jets in the primary.

HELP????
Chuck

Try giving it more choke. It sounds like it's starting up on the accellerator pump shot you gave it but is going lean once that's used up. At 3/4 closed you aren't getting enough choke. Adjust the choke (cold) until the blades are only slightly open (1/8" or less) and see if it helps. If you still have trouble, try adjusting them to where they are fully closed (but no more). If everything is working properly, the plate should open about 1/8" once the engine starts.

Sounds like the plate may be completely closed, "choking" airflow. Its supposed to be open a little (when the choke is fully engaged).

Depending on ambient temperature, the choke should be SHUT TIGHT with the engine off. As soon as it starts, the choke pulloff piston in the choke housing should open the choke enough so it doesn't gargle on gasoline.

It would be pretty common for the pulloff piston linkage to not be properly adjusted. It would be pretty common on carbs with INTERNAL vaccum passages to the piston to be missing the gasket that seals the passage.

Thanks Schurkey. I got the problem, and that makes sense. How do I check/fix it?

Thanks
CB

Do all Holley carbs have that pull-off piston, or is that a oem-type holley deal?

Well, "Cold" means different things to different people...but if the car doesn't run right when you first start it, and runs good when warmed up, the choke is the first thing to check.

Pop the air cleaner, and with the engine cold, verify that the choke blade will totally shut when you move the throttle open. The choke coil should "probably" be set right on the index mark. The choke coil is adjusted to provide proper OPENING speed. It is a mistake to adjust the choke coil to get the choke to CLOSE when you want it. Doing this right often means the choke blade will snap shut like an alligator eatin' chicken. Yup, that's the way it works...

Have someone start the engine, and the choke blade should pop open "about" 1/4 inch-maybe a bit less. Holley probably has an official spec for this, and that spec would be the best starting place--but I couldn't find it. LISTEN to the engine, open the choke blade a touch, and see if it runs better. Or close it a touch, and see if it runs better.

Adjustment for the pull-off piston (choke qualifying) is on page four, figure 15 of:
http://holley.com/data/Products/Technical/199R8339.pdf

On carbs using an INTERNAL vacuum source, be sure the vacuum passage is sealed with the tiny gasket, or the piston has no vacuum to power it. Those carbs with EXTERNAL vacuum use a goofy hose that is bigger on one end than the other. Make sure the hose seals tightly on the tiny nipple on the choke housing.

EDIT: The usual Holley carbs with an electric or hot-air choke mounted on the side should all have this piston. This includes the electric-choke conversion kits. Other carbs use a seperate diaphragm. If you don't have an automatic choke, don't go looking for the choke pull-off.

Schurkey, You ARE the man!

I closed it with a tiny gap left open and fired it up. No popping, it opened the buterfly fully within 45 seconds. It ran smoothly... and I owe you lunch.

Now to take it out and check the primary jets. I think I have a handle on that. Thanks Schurkey!

Chuck

It's 13 degrees above zero here. Unseasonably warm--I'd normally expect near or below zero. The crappy weather is yet to come. Yeah, you get to work on a lot of chokes around this place.

Thank you, and enjoy!

(edit) I'll be in Stockton, CA sometime in February. You can buy me lunch then...

Glad to hear it all worked out for you, Chuck. :thumbsup:

Thanks Darren. You and Schurkey have solved almost all of my Holley problems. I really appreciate the help. I'll keep you "posted".

Schurkey, I live right over the Altamont Pass just west of Stockton. Let me know when you are going to be here. If I'm not tied up, lunch is on me.

Chuck