Pat McPherson

Hi Guys,
I've been having trouble with my engine and need to check the fuel pressure. It sounds like the pump is cavitating or going bad.
Its a 1996 MEFI-1 ECM with the Cool Fuel System.
What should the fuel pressure be?
Thanks.

Ken N

My Mercruiser shop manual only goes back as fare as 1997,the fuel pump pressure specifications are 42 psi for a 7.4MPI, 454 MAG, 502 Mag.

Pat McPherson

Thanks but I think that is for the MEFI-3 ECM engines.
This 1996 I have seems to be an odd duck...

HiPerf2000

iTrader: (2)

thought the 96's had the VST tank up top.....with no cool fuel.

Young Performance

I'm not positive, but I think it's 32 psi.

Dave_N

It's 36PSI for MEFI 1, 43PSI for the MEFI 3.

Pat McPherson

Thanks Dave...
36psi sounds right.
Speeking with Mark at Precision he knew it was more than the low 30s for the VST tank engines but less than the 40+ for the MEFI-3 engines.

ThruHull

Pat,

any updates on your engine problems?

Pismo10

i concur 36 for the mefi1 which is the 1996

Cole2534

iTrader: (1)

Hmmm, I'm only getting 27-30 psi. Think that would cause the engine to run a little hotter?

I'm getting 180-185 with a 160 thermostat and this trouble began when I had a fuel pump fail.