Starts good, but when it warms up, it coughs and sputters. Has new plugs and wires. Carb was supposedly adjusted.

 

I would have thought Grindman would respond to this , it's right up his alley ,but he possibly hasn't read it yet.
What I would consider checking is the accelerator pump for delivering an adequate squirt when depressing the accelerator pedal. Some of these carbs had a diaphram that got tired and required replacement.
One of the ways to check is to remove the air cleaner and look in the carburetor when depressing the accelerator pedal/linkage. You should see two healthy squirts throughout the stroke of the linkage movement from the enrichment jets. If the choke blade is in the way , just rotate it down or up so you can see in there.

You would do this without the engine running !

 

you're correct Hanky I haven't read yet. so when it warms up it coughs and sputters and then straitens up at idle? usually if it does that the choke is either set to rich and the idle air mixture is too lean or you could have a timing problem or the float(s) sticking depending on how fast you move the gas pedal? another thing to check is to have someone look at the exhaust pipe and tell you if there is any black smoke coming out of it.

 

No black smoke. It starts easily hot or cold. After it warms up, I have to accelerate slowly, if I get on it, it coughs and sputters. Doesn't do it when cold. Think it's time for a carb kit?

 

is that four bbl carb the one that was put on that engine from the factory or is it an aftermarket? very few 302's came out with the four bbl carbs. and yes a carb kit won't hurt a bit if done right and properly cleaned inside and out with all new inards

 

It's a 1/2 ton van. Came out with the 4 bbl. My in laws bought it new.

 

one of two things are happening when you push down or stomp on it the choke ain't open all the way up and or the accelerator pump may be shot possibly both. if you do decide to put in a kit make sure that you follow the directions that come with it and that you clean it through out the carb using a good carb cleaner preferably the soaking kind I can't remember the name of it

 

If you can't find the stuff Grindman suggests, You can always get 2 or 3 cans of carb and choke cleaner that come with the soda straws and get a pretty good clean job with that. Just make sure you use that stuff outside in plenty of fresh air. It will dissolve carbon and grease with no trouble.

 

Thanks. I went thru a carb rebuild class 40 years ago, but don't remember much of it.

 

Not to worry, it's like riding a bike, it'll come back to you !