Hello all, I'm new on this forum so I hope I'm following proper protocol by posting this issue on this particular thread.

First of, I have a 1985 Chevrolet C10 with a Goodwrench 350 that has stock internals. Around July I installed a remanufactured Edelbrock 1406 to replace the original carb. I had to use an Edelbrock manifold adapter plate so everything would mount up correctly. The carburetor comes from a reputable source, National Carburetors. I also have two fuel filters. One before the fuel pump and one before the carburetor. Since then it has run without any problems until recently. When I start up the truck cold, I pump the throttle once to give it a shot of fuel and set the choke. It'll start up and run fine until I tap the throttle to release the choke. Then, when it's idling off choke, it'll slowly start to sputter then die out. Then a small amount of fuel drips from the right side (from driver's view) of the carburetor. What's more is everything off idle is just fine. I can run WOT, cruise, and accelerate without any problems. it's at idle that I have the problem.

Some possible explanations I've thought up is, 1) Fuel pressure to high. I'm going to replace the fuel filter before the carburetor with a fuel pressure gauge to make sure I have 5 psi to the inlet. 2) Plugged bowl inlet. Perhaps the float is not able to seat properly, resulting in a flooded engine at idle. If the pressure is satisfactory, I plan on splitting the carburetor to examine and clean the fuel bowl inlet and check the float height to 7/16". 3) manifold vacuum leak. I might also check the area between the carburetor and manifold for leaks. I read that one can spray starting fluid around that area and if there is a sudden, momentary increase in RPM, you have an indication of a manifold leak.

I know this a lot to read. I appreciate the patience and any insight.

 

The choke plate isn't set correct.

 

What kind of adjustment would you recommend?

 

I'll also add that the choke is wide open after I tap the throttle. The primaries seem to have a clear, unobstructed opening.

 

Choke plate cold should be full closed. If you have fuel running out of the carb top, it's a float issue. I check floats with holding them under a pail of water, if it floats, it's good. Setting the float drop, I do by hand, there is a scale you set it by from float tip to top of carb plate with gasket. If this is a hot air choke, it should remain closed until the choke spring heats up, and raises the arm to open the choke plate.

 

I tried adjusting the electric choke with the three screws on the side. Same results. I now plan to split the carburetor in half and check float height along with making sure the needle has a firm seat.

 

All,
Issue is resolved. Split the carburetor to examine internals. In one float chamber needle seat, found a small piece of rubber-like material preventing the needle from fully closing the fuel off. Sprayed carb cleaner through inlets followed by shop air. Float height was just under 7/16". Adjusted it to specs. Reinstalled carb to find it had the same issue. On choke, engine idled fine. Off choke, it died. Screwed low-idle screws in to stops and backed off both 1.5 turns CCW. Adjusted until smooth idle at approximately 900 RPM was achieved.