Fuel pressure problems.... Questions....
 

Ok, on my port motor (1998 350 MAG MPI) I have a fuel pressure issue. I am checking fuel pressure at the fuel rail and it is about 10 PSI more then the SB motor at an idle. Every 10-15 second, while ideling, the pressure will drop 6 PSI for a split second and then spike right back up. When this spike happens you can hear a short whine/grunt from what sounds like the injectors.

Is this a problem with the stock cool fuel system regulator? I took it apart and checked the screen, no blockage at all.

Now to complicate issues I have Prochargers installed, for the above test I eliminated the boost referenced regulator. But this leads to my next question. PC instructions have you plumb their regulator in the return line from the original regulator, so in a sense you have two regulators in a row. They also state that the fuel pressure sender can be placed in their regulator. The fuel pressure at this location is not the same as what is at the fuel rails (15 psi lower). The fuel rails have more due to the stock regulator I would assume, especially if I have a bad regulator. Any thoughts on this?

Thanks in advance.

Re: Fuel pressure problems.... Questions....
 

ttt

Re: Fuel pressure problems.... Questions....
 

Where is the fuel filter in the system and have you changed it recently?

How are the props working out for you?

RD

Re: Fuel pressure problems.... Questions....
 

Fuel filter has been changed. I also checked the screen at the inlet to the factory fuel regulator.

As far as props go, they blow out constantly I have to ease into the throttle or I go nowhere. I only have a couple high speed passes on them, I was waiting on fixing this fuel pressure problem first. Fast pass so far is 77 mph with some blow out. I would like to try some 28 four blades.