riverboater

I want to re move vst tank and install electric fuel pump and a return line to gas tank 1993 38 special with 502's this thing always vapor locks has this been done

Ted G

iTrader: (1)

Tyler Crockett does it on all the 502 mags he updates. Call him and I'm sure he will tell you the best parts to use. 810-324-2720

silent lucidity

iTrader: (1)

search on here there are 100s of posts on this issue...
I talked to an engine builder that knows MPI's well and he said we can return the fuel from the VST to the fuel tank as well and problem will be solved.. I'm doing mine this winter..

I relocated my water sep filters away from the motors and ran braided fuel lines above the motor by the plenum instead of so close to the exhaust manifolds and that helped a bunch.

Mercrusier wants engines to run 180 temp but the eng compartment cant get above 172..WTF

28Eliminator

I removed MY VST last year during the rebuild. I installed 1/2 lines, an aeromotive pump and boost referenced regulator for the blower. Never had a vapor lock issue since.

riverboater

So, should i remove mech. pump install elec.pump to feed vst tank and run a line from vst back to gas tank ? i have read that the vst return line is ran back to fuel seperator is this correct? Thanks

28Eliminator

I would not replace the mechanical pump and replace with an electric if you want to keep the VST, as I don't think it will fix anything. The return line from the fuel rail, dumps back into the VST tank. If the return was rerouted back to the fuel tank it might fix the problem, but I have never tryed that. The problem with keeping the VST is that some of the parts are not available anymore, like the fuel filter/strainer kit which was about $400.
The real fix is to eliminate the mech. pump & VST tank, but there is more to it than just that, as there is not really a bolt on replacement unless you can find a take off cool fuel system from something newer, and even some of them had vapor lock issues.