My 83 E150 (351W) is driving me crazy, instead of the other way around.

5 months ago, it started running really rough, especially at idle. I decided to replace the factory 2150 carburetor with a rebuilt one from ebay. That fixed the problem, until a few days ago.

With no warning, the engine started to run very rough at idle. When you free rev the engine, it is smooth. When you maintain a steady rpm, be it at idle or cruising, it skips pretty bad.

The plugs are black and you can see black smoke coming out of the tailpipe.

I took the carburetor off and inspected it. My first surprise is that no fuel was present in the fuel bowl. Maybe fuel is dumping past the power valve?

The power valve looks good, and from my understanding, they aren't so easy to blow out like they used to be.

Other than that, the carb looked good. No dirt or anything else unusual.

I checked for vacuum leaks with some starting fluid and all is well. I replaced the filter, plugs, wires, cap, rotor and coil during the first carb swap.

Before I chalk this up to a fuel related problem, could a problem in the ignition cause this? Maybe the module is firing erratically, or there is a problem with the distributor? If the ignition isn't working right, couldn't that foul the plugs and dump raw gas out the exhaust? Timing chain jumped? Blown head gasket?

It just seems really weird that carb number 2 is bad.

Also, I don't really like the 2150 carb. It is nearly impossible to set the air/fuel mixture screws while on the engine. I am thinking about replacing it with a 500 cfm Holley, which has the adjustments on the side. Will a 2300 bolt in place of a 2150?


I appreciate any advice and/or tips you can throw my way. I really need to get it running again asap.