Engine/Transmission (1998.5 - 2002) Why does new VP44 Injection Pump give me more power?

[RobbyRam]

I finally got my new injection pump installed, thanks to all the encouraging emails from the TDR. : Thanks to everyone)

Now, I have a new question concerning my performance... Why does my truck now perform, burning rubber, etc. , like the 'Comp Wire' is hooked up to the VP44, when it ISN'T! I also record a little less MPG's, but not less that 1 mpg.

Another oddity is my fuel gauge pressure gauge readouts.

Before the VP44 change, fuel pressure readings were: 15psi=idle

13psi @ 65 mph; and 11psi WOT.



Not, after the new VP44 injection pump install; my fuel pressure readings are: 14 psi @ idle; 11 psi @ 65 mph; and 8 psi @ W. O. T.



The plus side of all of this is that my 'Seat of the pants' 'get up and go' is way more now than before my pump change!

Could it be that my old pump restricted fuel flow, and this new one doesn't?

Bob in Sacramento

 

[ROADWARRIOR]

Sounds like your old pump was dying a slow death and not performing as well as when new.

 

[willyslover]

Bob. . glad it's working well for ya...



are you still trading it for a FERD ?

 

[rkressg]

If you looked carefully at the pump numbers, they (Bosch) has superseeded the old pump with a new pump. They probably changed something with the fueling in the newer model.

 

[HVAC]

Timing

One thing that was faulty with your old pump was the timing function. That's why some trucks won't start when hot. It's possible you now have a properly working timing circuit within the new pump.

 

[KOREDISH]

Good the hear your back running

Glad to hear you didn't throw in the towel.