Hey there, I am seeing 11 PSi fuel pressure at Idle, 10 cruising, and 8 when pulling a 6% grade at 2100 RPMs in 5 th gear. Heavy trailer. Is 8 psi adequate for my towing needs? Just want to make sure. I have had Cummins trucks since 89 but this is my first set of Gauges so I just want to make sure my cummins is getting enough fuel. Stock engine as well. Thanks!

 

Yes, you are fine. No need to worry. If you were getting down to 0-2psi then that would be a different story.

 

That's plenty, Monty. Most people don't see that pressure at idle!

 

Great! Well, I am trusting my Autometer electrical gauge!!. It is mounted about half inch from the CP3 Inlet. Thanks!!!

 

You got that right. When I had my LP on the filter housing my pressure was 8 psi at idle and would get down to 4-6 psi towing. Those LP's were weak.

 

On regular driving with the mods in my sig, I tend to see somewhere around 5 psi while drivign at speed. Should I be concerned and start looking at fuel systems, or is this acceptable? If I really try, I can suck the FP needle down to 2 psi under WOT, but not too frequently/easily.

 

5 PSI is pretty low, running the stack I would seriously be looking at augmenting your fuel system to help provide some better pressure.

 

Sure, I will spend your money! You need a fuel system upgrade!

Actually as long as you have positive pressure you are safe but you do not want to run down below 5 much if you can avoid it.

 

My stock pump only gave 8 PSI at idle, I could draw it down to zero so upgraded things.
I think as long as you're getting some pressure you're fine...

 

Your psi sounds fine. However, if you are worried, a cheap way to help fuel psi is to replace your stock banjo fuel fittings with high flow banjo bolts.

 

Actually Those were replaced with the GDP big line kit!

 

Big line kit replaces banjo from filter to cp-3, talked to GDP & he recommended also changing the banjo into the filter from the tank. Can buy @GDP under high flow banjo bolt or go to 90 degree pushlok fitting. Said once those restrictions are removed, that would be the max from stock lift pump.