New Engine, Similar Problem...

[jackn440]

Hey guys, I know I haven't been on for awhile. Just got my computer up and running again so I hope to be on the site a lot more. The car's come quite a ways since my last posts. I now have a '72 413 that I yanked out of a motorhome (yeah, that's right) in the Challenger. It's been in for a little over a year now, and it's been running great until recently. Nothing too beefy, 906 heads, mild cam, headers, performer rpm intake, and a few other necessities (orange box, etc.). I've been having an issue for the last couple weeks where the engine bogs (loads up?) during acceleration and around corners. I know you're thinking carb, specifically float level. I've gone through 2 different carbs now, the first one (which is the same Carter AFB that's stayed with the car through 3 different heart transplants, and just tonight I tried out an Edelbrock 1413 (pretty sure that's a 750). I pulled the Carter off, went through it, put it back on and no change. So I put the Edelbrock on to try and rule out the carb, no change at all. If I ease into the throttle it seems to accelerate fine, but if I mash the gas it will actually backfire while trying to pick up speed. Timing is set at 10 btdc, gets plenty of advance with vacuum. All plugs seem to be doing their job. It's getting plenty of fuel to the carb also (no regulator though). Only thing that boggles me is this problem just started out of the blue. Any thoughts would be much appreciated.

Thanks. Jack

 

[pagilman]

Jack, I have the same problem, I talked to a carb man at the cruise the other night, he said sounds like too much fuel pressure. Are you running an electric pump? Iam at 8 pounds and he said to turn it down to 6 for the street. My humble .02

 

[burntorange70]

Does it do it only after the motor is wormed up all the way? Could be heat soke. That style of carb is known for that. I put a 1/2 Phenolic spacer on my 340. Helped some.

 

[pagilman]

Turned my pressure down to 7 pounds and gave the throttle 1/4 turn and the dead spot seems to be better at beginning of the accelerator, but I think my main problem is the high rise edy, not good for the street, also no gears????????