Engine/Transmission (1994 - 1998) Fuel Pressure Readings

[henry_md]

What fuel pressure is the norm? I have a stock 95 2500. There are no performance aftermarket parts on the truck and no adjustments in this area have been made. In the last two weeks I have replaced the entire fuel delivery system.



From the tank to the engine, these items are new:

• Draw straw
  
• rubber to hard line
  
• hard line
  
• rubber to heater assembly
  
• removed heater element from assembly
  
• 90 rubber to lift pump
  
• Lift Pump
  
• rubber to IP
  
• IssoPro fuel pressure guage, with Tork Tek snubber on IP inlet
  
• Tork Tek Over Flow Valve
  

All new lines are 3/8" and rubber is marine grade. I also removed the original fuel filter and replaced it with a remote filter.



The pressure gauge reads 20# idle. When accelerating from a stop, it will drop to around 13-14#. When downshifting to come to stop, it will climb to 25# briefly and then drop to 20# when stopped.



Does the 13-14# sound right? I thought I read somewhere it should operate in the 20-25# range?



I appreciate any help in this area. I really do not want to waste my IP due to low fuel pressure.



Michael

 

[ata]

18 min psi under throttle, 24-28 idle, 28-32 2400 rpm's no load.

 

[Bob4x4]

Before you pull your hair out have you tried adjusting the over flow valve?

 

[henry_md]

Discovered I still have a very small air leak. I put the feed line into a jug of fuel and the fuel pressure moved right up. 20# idle and 28# at 2500 no load. Time to check each connection again.

 

[GAmes]

I found the easiest way to find a small air leak is to pressurize the supply line going to the lift pump. About 20 psi of regulated air will cause the offending opening to become visible with bubbling fuel.