86 chevy stall

[mason252]

My 86 chevy pu 350v8 starts to buck and cut out when I accelerate to to 40mph. It always happens when my vacuum gage drops to 10 in. Out of gear, I can race the engine all day long, it just runs and idles great, with high vacuum. I have replaced the wires, coil, cap,rotor. There is fuel in the carb when it stalls. What could be causing this, I am ready to scrap a really good truck.

 

[Bob]

Sounds like a clogged fuel filter or other fuel flow problem.

 

[Bob]

If it has a distributor with a vacuum advance "pod" on it, the wires from the distributor's internal pickup coil to the ignition module my be broken or shorting, and when the vacuum advance moves them, they fail.

 

[mason252]

Good thought, Bob, I'm checking that one out pronto. Ive got 5psi coming out of the fuel pump, but sometimes, I have to go out and rap on top of the distributor to get it to fire. I have another 86 chevy I do the same thing to. Its weird.