Help! My Chevelle was running great, and I got into it a little as I was merging on the highway, but I stayed away from the redline. I ran it up to about 80mph, and when I backed out of the gas, the car started surging so badly that I thought it was about to cut off. The car idles fine, runs if I barely give it any gas and will work up through all the gears, and goes like a raped ape at WOT. Give it more than a touch of gas, but not romp on it, and she falls on her face with the engine cutting off, or stumbling badly.

Here's my powertrain: 427 with iron heads, mild cam, Holley 750, HEI ignition attached to a 700r4 with a 2500 stall converter.

I've checked the timing, unplugged the vacuum advance, inspected the cap and rotor, checked for vacuum and intake leaks, and replaced the accelerator pump.

Any suggestions?

What are you running for intake? What carb?

Edlebrock Performer Intake...I think. (I'm out of town and can't check right now.) The carb is a Holley 750 with vacuum secondaries.

Sounds like a chunk of crap caught in the carb that's blocking the fuel to the transition part of the carb.

As posted above^.Crap in the idle feed restrictor.Holley has some issues with float bowls degrading.If so..give them a call,perhaps they will goodwill the carb and send you a replacement if you find carb material in the metering ckts.

I had an 84 Z28 that the charcoal canister came apart and filled the float bowl full of charcoal. That is exactly how it ran, fine at WOT, and at idle, but anything in between was poop!

Certainly sounds fuel related to me too.

Based on your responses, I pulled the carb, separated the bowl, metering body and base plate, cleaned them and put it all back together. It seems to run fine. I guess something got past the filter. Thanks for your assistance.

:thumbsup: Thanks for letting us know!