Jeepman71

Ok people it's time to show my ignorance in all that is diesel again.

I see most people use a pyro and a boost gauge. Why the boost gauge and not the fuel pressure gauge. Isn't there an issue with cummins and the lift pump?

If you were to use two gauges with an auto trans which two gauges would be most desired?

Thanks for helping clear some of my ignorance.

Jim W

The lift pump issue where with older Rams around the time frame of 2004.
Now the reason for a Boost gage is to be sure you do not lift the head and fail the head gasket when a tuner is used and the Boost pressure can reach 30 or 35 PSI. To prevent head gasket failures a lot of owners have change the head bolts to “ARP” Head studs with nuts. The 6.7L trucks seem to have eliminated for the most part any in tank lift pump issues. I have not read anyone really complaining about the stock lift pump if you are not running high horsepower engines that require more fuel than stock.

I have mounted my gages on the A-pillar and it is a tri-mount with Boost, EGT and Transmission temperature gauge. Fuel pressure would be my last choice as I am not using and type of auxiliary fuel pump.
Jim W.

Blake Clark

I like to run 4 gauges. Boost, EGT, Fuel Pressure, Rail Pressure,

If youve got a slushbox, toss tranny temp into the mix.

The fuel pressure is important, but not near as critical as with the VP44 trucks. The CP3 can draw its own fuel, and survive for a while. That while being eons longer than a VP44 can without a function lift pump.