Engine/Transmission (1998.5 - 2002) New VP44 exhibiting power loss compared to old one

[John - K5AWO]

My boy, PJ, just finished installing a new VP44 in his truck. 3500 SRW 98. 5



1) He is very happy to have it running again after being down for 74 days.



2) He is disappointed in that the performance curve is severely down graded compared to the power he had before the old one failed.



I drove the truck and here is what I noticed.

• 
  
  * Responsiveness: Almost nil to the point of being sluggish.
  
  * Engine wrap up at full throttle in neutral: very slow
  
  * Fuel pressure: 13# at idle, 9# at full throttle
  
  * New lift pump, moved to tank location
  
  * New fuel filter: 1/2 psi drop between inlet/outlet
  
  * Banjo bolts drilled out to 0. 193 inch
  
  * 30 mph cruise, stab throttle: very delayed reaction, transmission downshift slow (no torque to make it go).
  
  * Suttle throttle changes at 3-5 mph now give transmission the infamous 1-2-1 up/down shift stutter. It never did that with the old pump. More throttle and it went.
  

We have my dually 98. 5 CTD for comparison, so it isn't that we forgot how it used to drive.



Any thoughts out there on why a new VP44 pump would give less than normal performance??



John



EDIT: The APPS was recalibrated. forgot to mention it.

 

[AKAMAC]

John, that sounds like there is a timing issue. Is the key-way # matching?

 

[John - K5AWO]

PJ said that the old key has the #1030 on the it and that there are 3 arrows on the side of it. Also that it is made slanted which would offset the pump from the timing gear.



Unfortunately, he used the key that came with the new pump and didn't pay attention to which way it went in.



I agree, the way this truck runs is as if the distributor was retarded on a gasser motor.

 

[Gary - K7GLD]

Looks like first order of business will be to remove the gear and turn the key around...

 

[SEmerson]

Doesn't the pcm time from the cam position sencer

 

[Gary - K7GLD]

Doesn't the pcm time from the cam position sencer



To a small degree...

 

[n5ifi]

Well,,,,,,,,,,,,,,,,,,WHAT DID YOU FIND JOHN

 

[John - K5AWO]

Oh dear, I wasn't trying to ignore anyone. PJ has been driving it the way it is for now, retarded timing and all. Too many business clients eating up his mechanic time to "work on his own"



He and I are agreed that the key has to be backwards in the slot. We will definitely post when he turns it around. He is so disinchanted with the lack of HP and the way the transmission is acting, it really burns him up. Before the VP44 failed, the engine was strong and the transmission swift and sure. No so now.

 

[plongson]

That really blows to have to go back an re-work a job like that. Sorry to hear about it.