Kim72

BB 454, Holley 750cfm - 4160 carb (just rebuilt), timing set by Lars's tuning/timing paper.

Problem: starts and idles fine but if I try to get it over approx. 1800 rpm she dies out, like it is starving for gas. I believe I've set the floats correctly. It's getting a good shot of gas when I work the pedal. Took it for a short spin, under load, and barely got it back home. It was bucking and heaving all the way back.

I'm not exactly a Holley carb expert but I've tried all I have been able to read on line and I'm running out of ideas. Any help is appreciated.

Crepitus

Sounds like a delivery prob. pluged filter, crimped line, pump. Have you checked fuel psi?

Kim72

Yes I have a fuel pressure gauge and the pressure is right on.

larrywalk

Most carb problems are caused by ignition!

Kim72

I've tried changing the timing and the same thing happens. idles great and anything above about 1800 rpm I have to pump the throttle to keep it going. I have gas trickling out of the bowls at the screw holes so I'm pretty sure it's getting gas. Seems to starve for gas above idle. Starting to get frustrated!!

calwldlife

hmm,
could be the transition from idle circuit to power.
holleys blow power valves.
any backfiring before the trouble?

also could be ignition module

Kim72

No backfiring. New power valve from rebuild kit. I have 16 in. of vacuum at idle. Have a 65 power valve in carb now. Wondering if this is to small and if this could make a difference.

No ignition module. Points dist. with MSD box. Was running fine before new carb install.

Kim72

Fixed it!! Stupid me, I had the vacuum lines mixed up. I plugged them all and she ran like a scalded dog!! Sorted the lines out and now all is good to go.

Thanks for all the replies.