Ford Repair: Engine Problems, vacuum leak, wd 40

Question
I sent you an email once before about my 1966 Mustang.  Background information -- automatic transmission, Edelbrock 4 bbl carb, brand new spark plugs and pcv valve.  Here's the problem now -- engine starts and runs beautifully, however when you put the car in drive, it dies instantly.  It dies just like somebody turned the key off.  It also sometimes backfires gas back through the carb.  We adjusted the timing to try to get rid of that problem, but just not very much.

Answer
Rich,

The back firing would indicate a timing problem. I would also check for a vacuum leak, starting at the intake manifold and the base of the carb. The best way to check is start car and get a can of WD-40, with car idling, spray at the base of the carb and the intake. If the car revvs up, you have a vacuum leak. Hope that this helps and good luck.

ken