Following Midnightrider advise I put a nice gauge on the line before the IP that reads in the cab, had the hose made at My local hydraulic shop (love that place) and it is set to take up to 6k psi . Now the gauge is 0-15 with 1/2 lbs increments and when I turn the key ON it reads 5psi then when I start driving goes down to 3psi some times. I will set the filters before the pump so that I can get some more pressure to the IP but I believe I will need a new pump (I use electric) and will replace this one with a carrier pump I bought some time ago.

Now I read somewhere that this pump shouldn't have less than 3 psi at any time, is this right?

Thank You.

 

It's not unusual for the fuel pressure to drop under hard throttle. 3psi is the minimum spec from Cummins- at stock levels. If you're flowing more than stock fuelling through bigger than stock injectors, I'd not let it di pbelow 5psi.

What size supply line do you have going from the tank to the engine? Where is your electric pump?

 

I will put a stronger pump now and closer to the IP. The lines are 3/8 but the engine does not have other than stock injectors and the fuel up a few turns.