Fuel Pressure Question
 

I have a 98 12v. Will low fuel pressure cause higher boost while driving, and will it cause lower fuel mileage?<br>Thanks<br>Chuck

Re:Fuel Pressure Question
 

I dont see how low fuel psi. would make you run more boost, but low fuel mileage is definately an indication of low fuel psi. At idle it should be around 20-25psi of fuel.

Re:Fuel Pressure Question
 

I get lousy mileage. Perhaps I should look into a fuel pressure guage. Can a shop check that for you? Or is a guage the cheaper and easier way to go?

Re:Fuel Pressure Question
 

[quote author=bigbaddiesel link=board=16;threadid=9815;start=0#94223 date=1043105040]<br>I get lousy mileage. Perhaps I should look into a fuel pressure guage. Can a shop check that for you? Or is a guage the cheaper and easier way to go?<br>[/quote]<br>A Cummins shop or dealer should be able to check fuel pressure for you. Requires a special (metric threaded?) adapter that fits on the banjo bolt on the fuel filter housing, allowing standard gauge line to connect. TST Products was selling the adapter last I checked (~$25 us). Should only be used temporarily, as the gauge will probably eventually fail and lock due to the lift pump high peak pressure (pulses). Ran mine for a few days and wasted 2 gauges in the process. Worked though... The URL for the TST adapter is: http://www.tstproducts.com/service_tools_trial.htm<br><br>Regards,<br>-Scott