77 f250 4x4 351m

With the old 4160 600 cfm holley that leaks from every linkage and gasket on it the truck runs perfect. But i take the truck avenger 670 right out of the box and bolt it on and it bogs bad at low rpms, it will bog bad enough to stall right out as i pull into traffic or shift gears.

Iv been on the phone with the holley techs and they say there was a recall on these carbs a while ago. The part# on the carb says my first carb was the updated one but it showed the same symtoms as the first model so they replaced it with a second, I just bolted it on and still the same problems. It is almost undriveable with this carb. again I put the old carb on and it runs like a champ.

Im waiting for holley to call me back again here but i dont think theres much they can tell me. Anyone had problems with a truck avenger


-gbm-

 

Did you connect the vacuum advance to manifold vacuum or ported vacuum, and did you set the timing with the line disconnected and plugged?

 

I connected it to the ported spot on the carb, I checked the initial timing with the line unplugged and blocked on the engine side.



-gbm-

 

If it's the factory distributor, you should plug it into manifold vacuum. IIRC, ported vacuum only makes about 6", while the manifold vacuum can be three times that, so the spring in the vacuum advance canister may be too strong for ported vacuum to fully activate it.