What Is The Fuel Pressure Specs For 350;Mag MPI At The Rail?

[driz]

I’ve got a 2005 Regale that died to a stumbling crawl from plane last week. It stumbled in and would restart easily but run onIy at idle. Later I opened up the Cool Fuel 3 module filter section expecting water but was clean as was the filter. I sucked out 20 gallons running it through Mr Funnel and it was totally clean. The pickup tube and screen was immaculate as well. I was advised to change out the aluminum anti siphon and put in a brass model which I did. The aluminum one did seem to have a tad of inside corrosion in the check ball track. I later had it all going again and put my gauge on the schrader. It was around 36-38 vibrating at idle ( on bibs). Reving it past 3000 ( bibs)it got a more steady 39-40.
I’ve scoured the net and can’t find any real solid specs on fuel pressure limitations. I have seen 43PSI to minimum 36 with no further info on RPM , loads , conditions ect….. I don’t want to take it out to try it until I get an idea because this old beast don’t paddle….at all.

 

[alldodge]

The spec for your motor is 43 psi
The pressure at idle will be lower, and if you remove the vacuum line from the regulator it should go to 43

Keep in mind the accuracy of the gauge your using may not be perfect

 

[driz]

The spec for your motor is 43 psi
The pressure at idle will be lower, and if you remove the vacuum line from the regulator it should go to 43

Keep in mind the accuracy of the gauge your using may not be perfect

Thanks for the reply . I’ve had a couple Chevy trucks so the gauge is. Gotta have . It’s A Good one, whole set and actually new probably used once Or twice at most.
I know the GM MpI mantra by heart , 50 PSI or ignition goes bye bye, well more or less. Also that the GM in tank pumps were/ are and do set the standard for garbage. Those worked fine till they just stopped.
These marine setups cofound me. I’m starting to think that the anti siphon valve was not quite bad but just corroded enough to hang up that ball If there was a slight drop and it was situated just right. I had a hard time finding a difference between the new brass and old aluminum valve though it got chucked anyway.
One thing I didn’t do was check the values with the regulator vacuum unplugged.

 

[Scott06]

These marine setups cofound me. I’m starting to think that the anti siphon valve was not quite bad but just corroded enough to hang up that ball If there was a slight drop and it was situated just right. I had a hard time finding a difference between the new brass and old aluminum valve though it got chucked anyway.
One thing I didn’t do was check the values with the regulator vacuum unplugged.

you can always use an outboard tank or put the fuel line in a gas can temporarily to test.

Last weekend I was trying to take the antisiphon valve off my friend boat and it snapped off... when we rigged up an OB tank that bypassed it it still ran the same chitty way so I broke the valve for nothing...