I am overlooking something, symptom is truck will start very easily, and as long as the rpms are up to around 1300 it will run, just will not idle, dies instant when clutch is pushed in and no pumping of the gas; it appears that the fuel pump is dumping fuel, fuel filter is new, complete tune up, timing also appears fine, while running at such higher RPMs there is not spitting backfiring, could use any feedback that might help Me, Thank You.

 

Check that the EGR valve is working - not stuck open.
Please tell what engine you have. EFI or carb etc.

 

300 6cyl carb sorr bout that

 

Adjust your mixture screws, sounds like they are out of adjustment. After that set your curb idle to the specs off the emissions sticker.

After, if you have a timing gun it wouldn't hurt to reshoot your timing and adjust according. Block your timing advance.

I had the same problem, truck wouldn't idle and when transmission was engaged the truck would stall out. Rebuilt Carb, checked vacuum hoses ect and solved the problem.