Mercruiser 7.4 MPI - Fuel Issue

[bigwhite]

I have searched and searched and I cant figure this out.

Switched motors and ECM from a 98 7.4 LX to a built 99 7.4 Magnum MPI.

So far the swap has gone great without issue.. but I am stuck

When I turn the key on the fuel pump kicks on and wont kick off.. Forcing fuel thru the VST and out the vent line. Its a steady stream of fuel out the vent line not just a little drip. I think I have the fuel pressure regulator set up correctly:
Out of the fuel pressure regulator in the cool fuel system with a T and to the fuel rail regulator and to the pendulum.

I have pulled the VST apart a few times and cleaned - replaced the diaphram. Didnt help

I dont get it.
Any ideas?

 

[bigwhite]

Found it.

Green and white wire was not sending the ground signal turning off the fuel pump... 8 Hours later

 

[achris]

Hello bigwhite, and :welcome: to iboats.

Glad someone came along and helped you...

Chris...

 

[tpenfield]

:welcome:

tell us us more about the engine swap. Are you using the ECM from the old engine on the Magnum engine?

 

[bigwhite]

I had a high hour 1998 Mercruiser LX with the throttle body in it and I always had issues with it. It was tired.

I pulled it out and was deciding what to do when a complete 1999 mercruiser 7.4 Magnum MPI popped up on craigslist.
Tore the new motor down completely and sent to the machine shop: bored, new pistons, cam, turned the crank, had the heads gone thru etc etc.
Put it back in the boat.

I think its all hooked up and running but 2 wires at this point that I cant figure out.

It has the Cool fuel electric fuel pump, and the VST. I cant find a wiring diagram that shows both of these. Am I correct that the grey wire out of the fuel pump relay goes to the VST + and the electric fuel pump? Or what wire + connects to the top of the VST?

Any help would be awesome.