The Stovebolt Site Forums The Shop Area General Truck Talk Fuel Delivery Troubles

I bought a 65 C10 about 3 months ago, it as a rebuilt (45000 miles since rebuild) 350 pulled from a 71 Nova SS, and a four barrel edelbrock carb. The previous owner didnt treat it well, evidenced by the pitch black oil that came out as soon as I got it home, but it has run strong since I have gotten it. The only problem is when at 3/4 to wide open throttle, the engine stutters as if there isnt enough fuel being delivered. I live in Colorado, and haven't retuned the carb since I drove it from Kansas, so the carb should be running too rich. Any ideas to solve my problem?

First I'd get a carb kit and clean the carb good. The carb kit will give all the settings for the carb, float level (first suspect), air valve spring, choke rod, etc.... If that doesn't correct it then there is another possible fix. You didn't mention how long you were holding it at 3/4 throttle. For this fix to be a problem I would think you would have to be holding 3/4 throttle for some time, like climbing a hill. One of the things that is not paid attention to when installing a V8 is the fuel line. Chevy trucks from the 60s with a six cyclinder have 5/16 steel fuel line from the gas tank, V8s have 3/8 fuel line.

Larry

Pull a plug and see if its white or black. Black would indicate too much fuel. If its stutters and seems to lack fuel, it could be a fuel filter. If the plug is white, check fuel delivery.

Check for rust in your fuel tank. My 66 began to be fuel starved until it would only run for a few blocks. I pulled the tank and dumped out about 2 inches of rust. The rust was covering the fuel pick up line. It would idle Ok but anything past that caused starvation. I coated the tank with a good gas tank sealer after cleaning. End of fuel delivery problem. I would check the size of the fuel line too like Griffin said.

Another couple of things to consider. Typically if an engine starves for fuel under heavy throttle it will just bog or lose power and slow down, as soon as you back-off the throttle the engine will pick right back up. If it is popping out of the carb under heavy thottle, I would suspect weak ignition - can't produce enough secondary voltage to fire the plugs under load. When was the last time the plug wires and coil wire were replaced? How about the coil itself? If the engine has points ignition a loose or failing condenser will give the same symptoms. Another less common possibility is a flat camshaft. An engine with a cam going flat will run great until loaded up then it will pop or bark back through the carb. This can be checked by pulling the valve covers and watching the rocker arm movement at idle. They should all open the valves the same amount. If the cam is flat you will find one that is hardly moving at all. John

A coupla things on the Edelbrock carb. First, there are (should be, anyway) three holes that the accelerator pump linkage can be installed in. The middle one is the factory default. This linkage is at the left front corner of the carb. You can try different settings to see if this helps. If it's not getting enough fuel shot into is as the seconddaries open up, it could cause the kind of symptoms you're describing.

The other thing that is kinda important (because there's a lot of misunderstanding about it) is that the two adjustment screws in the front of the carb are only for the idle mixture and will not affect the operation at any time other than idle. In theory, anyway.

Finally, if you need to change jets or metering rods, you'll need to get a "tuning kit" that includes several sets of jets and rods. The metering rods can be replaced without removing the airhorn (the top of the carb) but you'll need to remove that if you want to change jets.

Ohhh...one last thing. If the carb has an electric choke and it's disconnected, that doesn't mean that the choke will never engage. The opposite is true. The choke will be engaged all the time, or at least until the underhood temp has gotten pretty darned hot. This can cause all sorts of problems, such as running rich, flooding, black smoke, etc.

Let us know how things work out.