360 Running Rough

Tech Question



Dear Rick, I am writing on behalf of my son. He has a 1969Coronet station wagon, 360 (1 yr old reman’d long block}, Edelbrock intakeand carb, electronic ign., stock exhaust and manifolds. The engine had beenrunning rough when accelerating but eventually smoothed out. I suspectedvacumn advance. He applied suction (oral) on hose at carb end, resulted inno change in RPM. He installed a new MP dist. and it seemed ok. Now it runsrough all of the time. He had the vac adv hose hooked to a carb port thatwas pulling strong vacumn all of the time. If he unhooks the hose it runsbetter. If he covers the port with his finger it runs rough again. I toldhim to hook the hose to the other port. It still runs rough. He looked downthe throat of the carb and noticed fuel dripping down the venturis. I thinkhe has junk in the needle/seat and it is possible he has the timing/idlesettings off. What do you think?



Three observations…

> Carb problem – as you noted – float level too high for whatever reason (orexcessive fuel pressure).

> Vac advance gotta be hooked to ported spark fitting. If all have vacuum atidle, throttle blades are open too far at idle. Complex tuning issues atwork here, but, most likely, not enough initial advance. Could also be rotorphasing or reversed pickup coil wires issue.

> MP distributors came with a terrible spark curve and achronically-troublesome advance mech. Best bet, if you don’t wanna “goinside”: Go to Rock Auto or AutoZone, buy a reman distributor for a 72-73340. That’ll get you a lot closer right away.


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