Lately the motor in my 76 Valiant has been running really rough, and I can't figure out why. Fuel Economy has gone way down. All of the ignition components (with the exception of the Electronic Ignition box) have been changed, all the filters are fresh. The car starts up fine, fast idles smooth, then when I tap the pedal to kick down the idle, it runs rough. I figured it's a choke problem, but it doesn't get better as the car warms up. Sometimes it goes away, other times it doesn't. During highway driving I can feel the engine surge and stumble repeatedly, get occasional back firing, and a strong smell of fumes. Anybody got any ideas?

You'll find the trouble in your fuel system. Prime suspect is the carburetor, followed by the EGR system. I'd home in on the carburetor's power valve, which is probably ruptured, stuck open or has fallen apart. Gotta love those Holley 1945s...not!

Do you have a spare carburetor you can swap on? Maybe now's a good time to do that 2bbl swap you might've been thinking of.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Unfortunately I don't have a spare carb lying around...I do have a a rebuilt Rochester 2V and an Autolite 2V in the shed, if that helps I thought about a Super 6 swap for a while, but I think I'll stay thrifty with the 1V.

Well, there just happen to be two brand-new (not rebuilt) Holley 1945 carbs on ebay right now.

Here, Here.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.