I have a 24v 5.9 Cummins 1999 with the vp44 injection pump that doesn't have the power it once did. My fuel pressure is 12 at idle speed and 10 at WOT... The engine runs fine, starts very good, and no smoking of any color. It's very slow on take off, barely gets to 2,300 RPM only on a down hill it would reach as far as 2,8000... All my fuel fuel lines and fuel filters are NEW... PLEASE HELP I'M OUT OF TRICKS...???

sounds like a map sensor reading 0 psi or disconnected

 

Any codes when you scan?  

@Mopar1973Man will have a few things to say about fuel pressure too

Had same issues with my MAP dropping out. Mine was a bad splice in a wire that you should not have unless someone got cut happy on your wiring harness. A bad sensor will do the same thing. Like @Me78569 says check it for trouble codes before you just throw a sensor at it.

 

16 hours ago, Eudie said:

My fuel pressure is 12 at idle speed and 10 at WOT...

 

15 hours ago, 2000Ram2500 said:

@Mopar1973Man will have a few things to say about fuel pressure too

 

Fuel pressure is too low for sure. 14 to 20 PSI at all times.

 

I've got to ask the same question any error codes too?

 

Then I've got to ask if there is any excessive AC noise that could be fouling the ECM up too. Might want to just have the alternator test for safety sake. 

Boost leaks?

2 minutes ago, Dieselfuture said:

Boost leaks?

Boost leak should cause black smoke issues.