Mercruiser 5.7L Fuel Pressure Regulator ?
#1
Mercruiser 5.7L Fuel Pressure Regulator ?
Engine is a 2003 5.7L 350/300HP.
Narrowing down a low fuel pressure issue. Removed the cool fuel fuel pressure regulator ( a real bear to get to and remove )
A few questions:
Thx
Narrowing down a low fuel pressure issue. Removed the cool fuel fuel pressure regulator ( a real bear to get to and remove )
A few questions:
- I'd like to test the fuel pressure regulator's function while out of the boat - is this possible ? If so, how do you do it ?
- Or, I'd replace it - is there an aftermarket or GM equivalent to this part ? The part # is: 861126A 1
- The fuel filter screen that sits under the pressure regulator is still seated in the cool fuel housing - it looks good from what I can see, besides it's in there pretty well and might be a PITA to remove. Does the fuel flow through the FPR into the screen or from the cool fuel housing, screen into the FPR ( this will let me know which side of the screen would have gunk - if any.
Thx
#3
Registered
iTrader: (1)
The regulator opens when the fuel pressure exceeds its setting, in your case is 43 psi. When it opens it sends the fuel back to the fuel filter
To test the Reg, remove it and use air. Slowly increase pressure watching a gauge to see when it opens.
To test the pump, you need to run it with a gauge which can read 100 psi and connect gauge to the output of the pump by itself.
To test the Reg, remove it and use air. Slowly increase pressure watching a gauge to see when it opens.
To test the pump, you need to run it with a gauge which can read 100 psi and connect gauge to the output of the pump by itself.
The following 2 users liked this post by AllDodge:
speicher lane (04-06-2021), tpenfield (04-15-2021)
#4
Ok - great - I can do those tests.
sounds like I’ll have to put a ‘test’ cover plate over where FPR normally seats to do fuel pump test. Correct ?
which direction does fuel flow ? Forward to aft or vice versa ?
will I do damage to fuel pump by inhibiting fuel flow with the gauge in place ?
sounds like I’ll have to put a ‘test’ cover plate over where FPR normally seats to do fuel pump test. Correct ?
which direction does fuel flow ? Forward to aft or vice versa ?
will I do damage to fuel pump by inhibiting fuel flow with the gauge in place ?
Last edited by ABL1111; 04-06-2021 at 12:55 PM.
#5
Registered
iTrader: (1)
sounds like I’ll have to put a ‘test’ cover plate over where FPR normally seats to do fuel pump test. Correct ?
which direction does fuel flow ? Forward to aft or vice versa ?
will I do damage to fuel pump by inhibiting fuel flow with the gauge in place ?
#7
Registered
iTrader: (1)
THE cool fuel side is the outlet return)
#9
Registered
iTrader: (1)
Blow into the inlet.
#10
I just tested the FPR.
There are (3) openings once removed from the cool tube;
Is this the right test ? If so, it sounds like the FPR is OK. Is this a correct assessment ?
FUEL PUMP
If so, I will need to test my fuel pump. Something I loathe to do, just because I have to remove it from the h*ll hole its in. Is there an easy way to test the fuel pump while it's in place ? If not, and I pull the fuel pump - how do I test it while out ?
Do I provide a fuel source to pull from, connect to (+) and (-) source, connect PSI gauge to output side and read the results ?
Thanks !
There are (3) openings once removed from the cool tube;
- one that sits down on the cool fuel tube - there's an O ring
- The brass coupler that connects to a fuel line
- the vacuum hose nipple
Is this the right test ? If so, it sounds like the FPR is OK. Is this a correct assessment ?
FUEL PUMP
If so, I will need to test my fuel pump. Something I loathe to do, just because I have to remove it from the h*ll hole its in. Is there an easy way to test the fuel pump while it's in place ? If not, and I pull the fuel pump - how do I test it while out ?
Do I provide a fuel source to pull from, connect to (+) and (-) source, connect PSI gauge to output side and read the results ?
Thanks !