Expert: Brad Sears - 3/7/2008

Question
Greetings Brad:

I have recently come into ownership of my folk's 'T-Bird with the 312 CID engine and Ford-O-Matic transmission.  It has been completely restored mechanically and runs very well, except for one issue:  It hesitates upon acceleration from a stop, sometimes actually stalling unless the driver feathers the throttle or punches it.  I've checked the acceleration pump for correct action and have replaced a blown-out vacuum advance on the distributor, as well as tried different idle adjustments, all to no avail in terms of the hesitation/stalling problem.  I need to note here that this car had this issue way back in the '60's when I used to drive it while in high school, so it's certainly not a new issue!

Any ideas would be greatly appreciated.

Thanks in advance!!!

Answer
Back in the day I was a tun up and carburetor man at a metropolitan Boston Ford dealer.Vaughn Monroe (Racing With The Moon) singer and band leader bought a similar T Bird from the dealer. It had the same problem right from the factory. What I remember doing was to lean out the accelerator pump discharge volume. I shortened the stoke of the diaphragm linkage. The clue here is that when punched the car took off like the proverbial ape. But normal acceleration it would hesitate and stall. The rich mixture from the accelerator pump aided the rapid acceleration but flooded the engine out and caused the stall at low acceleration rates.
Brad