Electric choke help...

Hey all,
I switched the E-clone on my '65 Skylark back to the original AFB when I bought the car. It runs tons better now, with one exception. The original choke stuff is long gone, replaced by an electric choke, which I have transferred to the Carter. The problem now is that to start well cold, the choke adjustment needs to be rich, but once it starts, it spits smoke and runs like crap...if I go under the hood and open the choke flap, it smooths right out...if it's lean enough that it doesn't do that, it won't start well cold at all...which lever on the carb should I adjust to get the choke to open quicker, if any? Thanks!

Aaron

 

We do NOT recommend electric chokes on older vehicles with automatic transmissions, unless they are never driven when the ambient is below 70 degrees F.; but the normal problems are not what you are experiencing.

You posted that "The original choke stuff is long gone, replaced by an electric choke, which I have transferred to the Carter.".

How much of the original choke stuff was gone?

If you replaced ONLY the cap containing the electric heating unit (and sealed the area for the heat line); it will be possible to make the electric choke work, albeit never as well as the original.

If you replaced more (in particular the metal choke housing containing the piston), the housing from the e-clone may not be compatible with the Buick AFB.

There is a vacuum passage inside the metal choke housing which connects (with a rubber or cork gasket) to a vacuum passage taking vacuum from the passenger side primary throttle bore. This vacuum source activates the choke pull-off piston inside the metal housing to allow the choke to open after the engine starts.

The choke cap CLOSES the choke; the choke pull-off piston OPENS the choke.

Jon.

 

OK, now we're getting somewhere...I still have the original choke housing on the car, so I replaced the gasket around the vacuum port, but the choke still doesn't open far enough once the engine is running...the piston seems to move free, and it moved when I sucked on the housing (scientific, huh?). Where does the choke draw vacuum from? I have aluminum heat spacers under the carb, but I can't imagine there would be a vacuum source under the carb. I did use Edelbrock gaskets under the primary venturi clusters, but that's only because the ones I had from the Carter rebuild kit didn't fit well and allowed the clusters to leak, and the Edelbrock ones fit perfectly and seemed to have the same holes in them. Any other ideas or adjustments I can make? I appreciate your help!

 

The vacuum source is a small passage that runs from the primary throttle area on the passengers side.

(A) remove the metal choke housing.
(B) there are 4 points of the choke housing that contact the carburetor body.
(C) Three of these points are the mounting screws.
(D) The fourth point is the vacuum source.

Probably the first thing we need to do is determine if the electric choke is functional (after all, you did say it came from the e-clone p ).

Remove the electric choke cap, attach both a negative and positive jumper from your battery, and determine if the heating element in the cap actually gets hot. If not, we are beating a dead horse.

Assuming the heating element works, then we can procede with the choke:

Take a very thin wire, and insert in the vacuum passage in the carburetor body that you exposed by removing the choke housing. If you manually open the choke butterfly and the primary throttle butterfly, you should be able to see this wire in the passenger side throttle area (assuming the passage is not plugged, and you can insert the wire that far into the passage. This passage must be open.

If this passage is open, and the passage inside the choke housing is open, and the heating element works, we will be able to make the choke function, albeit never as well as the original.

Observe again the passage in the carburetor body. There should be a brass restrictor pressed into the line. This was a timing device, to effect how long the original choke would take to go completely off. This restriction may need to be opened up to make the electric cap work. Compare the orifice size of this restriction to the restriction in the e-clone. Since the cap is from the e-clone, it will be necessary to open up the original restriction to match the e-clone (thereby ruining the easy return to the better hot air type choke).

If you do open up the restriction, it would be best to remove the carburetor from the engine, so that no metal shavings go into the engine.

Best advice I can give: put the electric cap back on the e-clone and sell it to some Chevy dude; and return the hot air choke to your Carter.

Jon.