camshaft in 305 chev

is it possible for a camshaft lobe operating the mechanical fuel pump
to provide good fuel supply at low speeds, but weaken at higher speeds?
I dont seem to be getting enough fuel at higher speeds, and suspect
a lobe on cam operating fuel pump.
rdobbs

You may be confusing the camshaft problems on the late 70's and early 80's 305's with your fuel problem. I've never heard of this. Did you recently install a new cam? You might be sucking air in the line somewhere. Possibly incorrect float level, or maybe a clogged filter.

Need more info...

pamsdad, thanks for reply. its an 81 chev trk, engine has 30k,new fuel pump &filters,all vacuums
been checked,also new carb

What makes you think the fuel pump is delivering insufficient amount of fuel at hi-speeds? Need a better description here.

This might be a lean condition you're experiencing, especially seeing that you just replaced the carburetor. That's why I referred to the float level/lean condition theory.

Is it a bone stock 305? What carb did you put on it? New or rebuilt? I've seen many crappy rebuilds/rebuilders, best to rebuild yourself.

You say all vacuum has been checked -- OK. That's not what I was referring to. Their may be a pinhole in the rubber line BEFORE the fuel pump that is pulling air into the fuel line.

Hope this helps...

It is possible that the float level on the new carb is too low allowing it to lean out at higher rpms. Thats where I would start. But like Pamsdad said, more description is needed. What makes you think its starving for fuel? Running bad at higher rpms, have you checked the plugs to see what they look like? That will tell you if your running lean. You could even have some trash in the carb somewhere making it run funny. Just becuase everything is new don't mean it will be right. Sometimes tuning is needed.

trk is stock. rebuilt old carb before buying new rebuilt rochester 2b quad 2,no change.i backed down my driveway which is inclined, and trk died.trk would not start. sprayed carb cleaner in breatherand it started right up. i thought about the floats, but when both carbs did the same i assumed it wasnt that. on 6/30/04 im going to bypass the mech fuel pump with an electric one and see if this helps. im an old x hot rodder and have ran into about everything, but this 305 is puzzling. rdobbs

You have 2 threads about this problem...

The other one gives a better description of your problem.

Sounds to me like a choke adjustment...

Thanks guys for all your input, i will certainly check out the choke. One thing for sure, I will find the problem regardless of the time or cost, and if I find the problem before this thread expires I will post the verdict. rdobbs