Spitfire Spitfire 1500 - Stromberg CD 150 Question

[Flatlander]

I have been fighting a problem with my car over the last two weeks and need some guidance. Having replaced the original carburetor on my car with one that I had rebuilt I went for a test drive. Everything seemed to be going great when after 15-20 minutes the car would simply die. At first I thought it might be bad/loose ignition wires as when I checked the wires after a stall I found one of the wires loose but having replaced those the problem still occurred. I then thought of "vapor lock" as it has been extremely hot here but after the drive today the problem again occurred without the hot temperatures and within a short period of time. (I also had read that "vapor lock" only occurs when the car is attempted to be started after being turned off.) I now believe the problem is in the carburetor. If I drive the car keeping the rpms below 3000 the problem does not occur but when I run the car past 3000 rpms, after a few miles the car will stall.

Any ideas what area of the carburetor would be associated with such a problem?

Thanks,

Gary

 

[tdskip]

Any emissions controls on the car?

The coil and points etc are all known to be good? How about your fuel filter and pump?

 

[Flatlander]

The coil and points are new. Fuel pump seems to be pumping a good supply of gas. Lines and filters are new and filters are clear of any debris. No emissions controls on the car.

I forgot to mention that after the car dies I wait about 15 minutes and I can get it to refire and run again for a period of time. (Depending upon rpm range.) Today I removed the air cleaner immediately upon the car dying and the carburetor appeared "damp" with gas and in restarting it was similar to starting out a flooded out carburetor.

 

[Flatlander]

In discussions with others now I am not as sure the problem is isolated to the carburetor. Again electrical issues might be at work. Need to figure how to identify the component causing the problem when it occurs. Any ideas of what I can do on the road to diagnos the underlying cause of the problem? The problem I am having is that I can't seem to get it to occur in my driveway always along the road.

 

[tomgt6]

I would swap out the coil. If I remember someone said coils can misbehave when warm or hot. Put the old coil back in and see what happens.

 

[tomgt6]

The other thing to check would be the float and needle may be getting hung up and then the carb floods out. See if the float is full of gas as well.

 

[3798j]

Could be a clogged fuel filter. Happened to a friend on a Detroit vehicle. You could tool around in it ... no problem. Get it out on the highway and get on it....it would drone to a stop. We cut that filter open...it was filled with rust...and some gas.

 

[Rhodyspit75]

Drive with the gas cap open. The tank is vented through the carbon canister. If the line gets clogged then you will create a vacuum in the tank and not get gas. If you sit for a while then air can get into the tank letting gas flow for a while until it happens again.

 

[Flatlander]

Went for a drive tonight and with the exception of one very brief sputter could not get it to die. Makes me think the problem is electrical as it was cooler tonight. Will try in a couple days when the temperatures heat up. Mounted a timing light to the engine and ran it through the hood and under the wiper. Next time it dies will determine electrical or fuel.

 

[Dudly]

If you have a carb with the water choke that is always worth a look, enrichment needle stuck one way or another.
It is an evil thing