Power loss

2004 Dodge 3500 5.9 Cummins HO. 1800-2000rpm, 60-80mph

Power losses, motor runs but performance drops off, power on-power off surging feel. Main fuel rail pressure is 16410, boost is 39.7 (less atmospheric). What could cause this? Bad ecm ground, bad crankshaft position sensor-bad ground? Apps? Has new map sensor (high), new fuel filter, tons of different fuel treatment

Thank you in advance, Merry Christmas!

Does that say 1 amp on the fuel pump

Ninjaxchicken wrote: Does that say 1 amp on the fuel pump

It does, and that's (surprisingly) normal for these trucks. :silly: It's a misleading PID - the actual lift pump draw is higher than that.

Captiva, did you happen to save that data file? Any chance you could send it to me?

You need to be watching the actual fuel pressure, fuel pressure setpoint and the fuel pressure regulator % during the surging. That setpoint PID is good, but doesn't tell you if the rail pressure is matching it. WIth your foot solidly on the floor, the rail pressure should get to around 23,000 PSI.

This honestly sounds exactly like a fuel pressure regulator solenoid problem. Dodge calls it the FCA, Fuel Control Actuator, whatever. :lol: When these start to fail, you'll be able to watch the regulator % chase the rail pressure back and forth. This is because the solenoid pintle is sticking, and requiring more and more magnetic field strength to move.

Found an example of exactly this from a 2003 Ram. You can see the engine speed surging at idle as the fuel pressure comes and goes. The fuel pressure regulator and the fuel rail pressure are never happy. :silly:

hi tyler wonder if we can see a good wave of the fuel pressure regulator should these wave forms be more steady with a good solenoid

chief eaglebear wrote: hi tyler wonder if we can see a good wave of the fuel pressure regulator should these wave forms be more steady with a good solenoid

Yeah, they'll be much smoother with a working solenoid. The ECM will have no trouble getting and maintaining the rail pressure it wants.