Mopar Action On-line – Tech Questions
Bryce Carpenter, Prospect, PA, 1971 Plymouth Fury 440
Hi Rick, I’ve got a ’71 Fury, with a ’70 440 Commando,Carter AVS #4741, Edelbrock Performer intake, stock ’74 heads, bored .030,flat top Mopar pistons, Mopar purple cam #P4286677 (272º int./272º exh.duration, 0.455″ int./0.455″ exh. lift) factory hi-po exhaust manifolds, 727auto with the stock converter and a mopar shift kit and a 3.23 Sure Griprear.
The problem is that from a dead stop, upon accelerating normally, the carhesitates and I have to “feather” the throttle to get it going, then it’lltake off like I got into it. I’ve rebuilt the carb twice installing a newaccelerator pump, and tried installing different metering rod springs, butno change. The car has run like this ever since I restored it. It has about3,000 miles on it.
What’s the best way to fix it on a tight budget?
Bryce, there’s something missing, broken, or generally screwed up in thecarb’s accelerator pump circuit. Guaranteed! Assuming you changed theplunger, and it’s good, the problem is likely either a bad (or dirty) inletcheck ball assembly, or a poorly seating discharge needle, which can bere-seated by gently tapping on the top of the needle with a drill rod andsmall hammer.
It’s also conceivable that one of the passages, or the discharge nozzles(squirters) themselves, are plugged or badly clogged.
Should be an easy, obvious fix if you take the time to understand how itworks, then what the malady is.