Fuel Starvation?

[69 R/T]

I'm running a bone stock 440 in my restored 1969 R/T. The engine and components are equipped just as original. Carter AVS, Chrysler points ignition, Carter stock fuel pump etc. and all fairly new or rebuilt professionally. The problem is that when the air temp is warm, 85 degrees plus, when I accelerate slightly aggressively, the engine surges, bucks, chokes and "lean putts" until I activate the electric fuel pump, then it goes away. I am not running the vapor separator, just a Fram G12 filter at the pump like stock, which is how we all did it in the late 70's. Oh, the fuel tank is reconditioned too. Any ideas or suggestions?

 

[Meep-Meep]

So you have an electric pump in series with the mechanical?

 

[polkat]

What Meep-Meep said. "Bone stock" doesn't include an electric pump, and I don't believe that Carter made Mopar's mechanical pumps during those years (could be wrong). Sounds like the aftermarket electric pump (which I assume is further down the fuel line then the mechanical pump) may be choking off the mechanical pump when it (electric pump) is not operational (fuel starvation). You hardly need both on a bone stock build, even an R/T. Just a guess.

 

[Redpolara]

I think polkat just hit the nail on the head, expecting a mechanical pump to draw fuel from the tank through a switched off electric pump is a big ask.

 

[mopar_71]

X2 on the double pump setup.
Gotta ask why 2 pumps?

 

[69 R/T]

Ok guys, Here's the deal on the dual pumps. I bought the car restored, the previous owner installed that pump as a carb primer due to the fact that the car was rarely driven and didn't want to crank the engine too long to draw fuel. Perhaps ya'll are right that it's restricting flow. This is why I get on here and ask. Lots of good info and comments. I've never needed an electric pump either, but since it's on there, what the heck. Now I should remove it and see what happens. Thanks guys!!!

 

[polkat]

You could remove it....or use it and remove the mechanical pump. Either way should work, although I've found that an electric pump (that's not installed directly in the tank) is often too noisy on a street driven car. If it were me, I'd just dump the electric. This assumes that there is not problems with the mechanical pump. You can always prime an engine with a little gas down the carb.

 

[69 R/T]

My buddy suggested splitting it off so there's a direct line to the mechanical pump and still having the electric as a back up so the fuel doesn't strictly flow thru the electric pump. Seems like a hassle. I'll probably just remove it.