What would it do if you blocked the return line on a 24 valve? My buddy tried it on his with a ball valve and he said fuel pressure never droped below 20 psi campared his usual 11 PSI at W.O.T ? Would it hurt the VP at all?

 

I'd imagine that the return line is there for a reason and with these VP's being as touchy as they are I'd like to keep mine in working order. With that being said I'm going to clamp mine off here soon in order to try and find where my fuel prime is going to.

 

I would think that since th VP is cooled anf lubricated by the fuel passing through it, that if you block off the return you would not be cooling or lubricating the pump enough. Restricting the return will increase Fp but also heat up the fuel as well Just my $.02.
Joe

 

The excess fuel that cools and lubricates the VP44 is returned to the tank by the return line. If the return line is blocked, pressure rises because flow is decreased - but so is lubrication and cooling of the VP44. Not something I'd suggest doing.

Rusty

 

I tried replacing the check valve on the return line with a new one and it didn't cure my hard start. I don't think there's anything wrong with the old one. You can throw it in there and see if that helps if you want to.

 

rusty and cyric's got it