Uphill Sputtering/Choking at over 50mph

[C4UC101969]

Hi All,

The other day and today I was climbing a fairly steep hill at over 50mph and all of sudden it started to sputter and choke felt like it was not getting enough gas and both times gas tank is on full, speed started to go down and giving it more gas did not help at all, once got to a straightaway it started working perfectly.

Now also did a test of climbing an even steeper hill at much lower speed and it was pulling me upwards to 50mph with no hassle and no sputtering or choking at all.

What can it be, fuel filter possibly?

I got a 4barrel carb with a 307 and a three on a tree

[ElKotze]

Could be the fuel filter for sure. Don't forget the one in the tank.

[Steeveedee]

I'd start with the fuel filter, too. What carburetor do you have?

[68 P.O.S.]

What is your timing set at? Any recent work done to the engine? I agree with the above, check your fuel filter & sock and inspect the lines & connections. Do you have the correct gas cap?

[sick472]

I have a 85 K20 with a 350 and it does something very similar. I have found that a few of my plugs are fouling with what appears to be oil (the old engine uses oil pretty bad). If I pull the fouled plugs and clean them or replace them, it buys some more time. I think my valve seals are leaking in those cylinders (good compression tests), not so much that I witness oil smoke from the exhaust,but enough to foul the plugs over the course of a few months.

Hopefully your stalling is fuel filter, vapor lock, or gas cap related.

[C4UC101969]

Thanks guys I will check the filters as well as will take a look at plugs, cause I also have a leaking seal.
The gas cap I have on it is the correct one indeed.
Also the carb previous owner is not sure what make/model he just knows it came out of an old camaro engine.
Will report back on my progress.....