chevy questions

[zmancj]

I have a 81 cj5 with a 70's model 350 motor and th350 tranny. Here recently it acts like it wants to cut in and out when i get up to 65mph and now it is doing it at 55mph. I think it is something to do with the fuel or maybe the Catilitic converter is going bad. I have replaced the tranny gasket and fluid, it goes through all 3 gears smooth as can be. I have also replaced the fuel filter, and PCV valve. the carb was rebuilt in December and a new fuel pump was also put on at the same time. I figured i would see what yall think before i take it to the shop. Any help would be greatly appreciated. Thanks Zack

 

[Mac5005]

is the original cam still in the engine? Are you running a mechanical fuel pump? Checked all the engine grounds especiall the ones used for gounding the ignition system?

 

[zmancj]

The cam is original and it does have a mechanical fuel pump. I have not checked the grounds ill try that thanks.

 

[Mac5005]

another thing to check and make sure that the cam lobe for the fuel pump has not worn down.....if so it would cause a fuel shortage at higher rpms but would run fine down low.

 

[zmancj]

how do you check the cam lobe?

 

[rran64]

are you still running the small factory jeep fuel line you need at least 3/8 line and the pump push rod should move at least 1/2in in & out

 

[CB77GMC]

Sounds like pick-up in distributor to me. $.02

 

[zmancj]

Thanks