Distributor or carb?

A few weeks ago, i posted in the "engine topics" about a strange mis fire that i was experiencing.. my motor is a "77 305" out of c10 truck, according to the decoder.

Given the info that i received; there were problems with the heads and they probably need to be rebuilt... No problem understood. I figured that if i replaced the plugs, wires, cap, rotor, i would be ok for a while.

It starts and runs good at idle.

However, when put it in gear and start driving, i get a little sputter, and then it levels out at about 25 mph,, when i hit the gas, if feels like I there's a wire crossed (misfire),,, it feels like its skipping a cylinder.

I checked and set the timing,around 4degrees (seems to run best there), played with the idle a bit and still no change.....

I'm at a lost, not sure what to look at next... Is it my carb (Qjet) or could it be the distributor or its internals....

Ray

If I had to venture a guess it sounds like the accelerator pump on the carburetor is shot and should be replaced. They are pretty cheap. It's that or your experiencing a "Lean" condition on acceleration, which is a vacuum leak or that accelerator pump. My guess.

Rebuild the carburetor or replace it and the problem should go away. Its also a great time to rebuild that distributor. I did my HEI and it was about 25 or 30 dollars worth of parts including the Cap and Rotor. You need the Nylon Bushings on the counter weights, the Magnetic Pickup, springs, and the Electronic module. Or an MSD Ignition set up! :D If the Cam Gear on the distributor looks worn I'd replace that also. None of this is hard to do I did it.

I would not use a Cap that does not have brass contacts. Those cheap 5 to 7 dollar caps really sukkx.

If I had to venture a guess it sounds like the accelerator pump on the carburetor is shot and should be replaced. They are pretty cheap. It's that or your experiencing a "Lean" condition on acceleration, which is a vacuum leak or that accelerator pump. My guess.

Rebuild the carburetor or replace it and the problem should go away. Its also a great time to rebuild that distributor. I did my HEI and it was about 25 or 30 dollars worth of parts including the Cap and Rotor. You need the Nylon Bushings on the counter weights, the Magnetic Pickup, springs, and the Electronic module. Or an MSD Ignition set up! :D If the Cam Gear on the distributor looks worn I'd replace that also. None of this is hard to do I did it.

I would not use a Cap that does not have brass contacts. Those cheap 5 to 7 dollar caps really sukkx.

Now is a good time to do alot of stuff since, I've got that Cutlass up and running pretty good.....

Thanks for the info. I have a shop manual if i get in trouble rebuiding the carb, might even pickup a carb rebuilding book.

I've been considering the MSD set up, I'll keep shaking the money tree to see what falls out...