Flathead 8 Carburetor Problem

[BLoshoncy]

Hi,

I have a 41 Pontiac Coupe with a Flathead Eight. I just had the carb rebuilt and it idles fine and sounds great when it sits, but when I go to take off in first, it just dies.

Please help, I'm clueless when it comes to carburetors!

Thanks!

[carbking]

Check the advance module on the distibutor first. Next, check the setting of the two idle screws. The idle mixture control screw should be out approximately 1 turn from lightly seated. The throttle positioner screw should then be adjusted for the proper idle RPM.

A defective carburetor accelerator pump could also cause this condition; but you did say the carb was just rebuild. To check the function of the accelerator pump first start the engine (now you know there is fuel in the bowl). Now kill the engine, and remove the air cleaner. Make sure the choke plate (the butterfly valve at the top) is open. Observe down through the carburetor and work the throttle to wide open throttle. If the pump is working, you should observe a stream of fuel pumped into your view from the accelerator pump jet (about midway down in the carburetor). No fuel, the accelerator pump isn't functioning. Fuel, and you probably have other issues.

Jon.

[BLoshoncy]

Thanks for the help,

I imagine you are referring to the vacuum advance. I know there is vacuum getting to it, because I disconnected it and felt that there was suction. I know there is a diaphram in there, but I'm not sure how I would test to tell if it has gone bad. Or if it has enough vacuum to work properly.

There was a vacuum wiper on the system at one time that is disconnected now. There is just a bolt stuck into the end of the hose that went to the wiper motor. I dont know if that would mess up the advance though.

Thanks!

[Ron of Chicago]

The best way to check the vacumm advance is to put a timing light on the car and watch the mark. You should see a difference as to where the mark is between the advance being hooked up and not. If you do not have a timning light you should be able to tell if it's working by the engine R.P.M.'s. there will be an increase in engine speed when the advance is connected if you have vacumm at the line.

Did you look to see if the accelerator pump was working like carbking suggested?