I've got a 2002 SO CTD with a intank pump retrofit from the Dodge dealer. My fuel pressure @ idle is 7-8 # and can drop down to as low as 2-3# depending on how hard I am driving it. My question is will a pusher pump cavitate my in the tank pump.

Thanks, Ronnie

 

It would actually be the otherway around, the intank would cavitate the 'pusher' pump. If the pusher is rated at a greater flow than the intank, it would definitely be better to bypass the in tank setup with a draw straw.

 

Sounds strange. I don't think anything can cavitate the intank pump, simply because there is no restriction on its intake, no line of any significant length. Like Tare said though, if intank pump is much smaller flow rating, it may be a restriction on the pusher suction line. If they are similar, I would think all should be Ok.
-P

 

Many have tried to pull through the in-tank pump running and not running with our pumps. AND it simply does not work. Too much restriction can cause cavitation in the stronger up stream pump and it will eat the gear base up (in our pump design at least). Any aftermarket pump that is designed to be the sole pump on the truck works best with its own free flowing pickup. Any of our pumps will walk away from the in-tank pump so i see restriction issues there.

Now the flip side to this is to put the pump that can move the most amt of fuel closest to the tank and feed the pump that moves the least. An example of this is our 1009 12 valve kits. We feed the mechanical pump in that setup. This just gives head pressure to the pump so it can do its job easier.

 

I keep seeing the in-tank Walbro pumps that are similar to the popular GSL392 in performance, yet cheaper. I wonder if anyone tried these in a truck like ours. Some of them are 255 lph and 80 psi, pretty impressive, so you still would want a separate bypass line for that, looks like.
-P

 

Unless you are going to get rid of the intank pump you might install a big line kit instead of a another pump upstream. It's a good idea to get rid of the restrictions in the fuel system no matter what pump you are running.

 

That sounds like a good idea. I've got a gsl 392 that I'm really happy with but except for ease of replacement the intank pump is probably the best of all solutions.