Carb'd Chevy 350 Question - Carb backfire (1 Viewer)

[FJ40_owner]

My 40 has a 78 350 installed. I run a Rochester 2 barrel carb. There is no smog stuff on it. Recently when running at moderate rpm, say 2000, engine is warm, when I put my foot into it the engine will sneeze through the carb.

My stock 40 used to do this and the solution was a new gasket around the accelerator pump, as I recall.

The only PM I have done is fluid changes, air filter and plugs. The PM was done months ago.

I run regular CA fuel.

Should I check the timing or might something be wrong with the carb?
The choke is OK and not stuck closed.

Thanks,

BigJim

 

[Gumby]

Accelerator pump sounds like the culprit.

 

[baxter650]

Engine off, look down the carb throat, move throttle to w/o, look for pump shot.

 

[Gumby]

definitely with the engine off. You'll look goofy without eyebrows.

 

[NeverSummer]

definitely with the engine off. You'll look goofy without eyebrows.

LMAO! I have seen this happen!

 

[Chevinater77]

my 72 chevy 2 wheel drive long bed with a 350 with a 2 barrel carb does this with bad gas. We just picked the rig up so i plan to get a carb "rebuild" kit. and do the gaskets and new filters for it! Mine only did it around 50-60 MPH. and only when in drive. when i ran premium it stopped doing it so much but still did a little!