Newbie With an Engine Question

[mo-bronco]

I recently bought a '79 F150 4x4 short bed. It has a 351 modified. It started out running great, but now has a problem. It wasn't driven much so I've been going through and freshening things up when I can. When the problems surfaced I replaced the plugs, wires and dist cap. It's idling rough and when I press the accelerator it is sluggish and hesitates. When I coast, it's not bad, but when I give it gas is when I have the problems. I've wondered about the accelerator pump or a vaccuum leak. Any ideas? Thanks in advance.

[northerndave]

look down the carb with the truck not running & work the throttle linkage full stroke. look for 2 nice squirt gun shots or fuel. if you aint got it, then it's your accelerator pump for sure & an easy fix.

Always good to look for vacuum leaks too though.

[IZZYAZ]

Also check to see if the choke is working correctly. My auto choke just went out and had similar problems. Idle fine, rev fine, but under load would die out.

If that isn't the problem double check fuel filters. If it has been sitting a while, there maybe crap floating around in the fuel system and plugging the filter up. I have replaced (2) stock and (2) inline fuel filters in mine in the last 4-5 weeks due to crap in the fuel. I have the new tank, just haven't had a chance to get it in yet. I guess to many irons in the fire.

Another thing, rebuild the carb. I did mine. First carb I ever took apart and rebuilt. It was a 1000 times easier then I ever imagined. And it runs great now.

[Mil1ion]

351M

I would replace the fuel filter at the carb and also install a second inline fuel filter between the pump and the fuel tank.