Injection pump leak test cm2250

[Rockinbexpress]

    pressure keeps dropping below commanded then ramps up and pump sounds like crap when it does it. Pressure drop was 960 in a minute ill re torque and check again today mpgs are down, power is down pump was installed 8/1/22

[Rawze]

(04-23-2023 )Rockinbexpress Wrote:  pressure keeps dropping below commanded then ramps up and pump
...

and...

(04-23-2023 )Rockinbexpress Wrote:  ... In the meantime graph your commanded and measured fuel pressure and see if your measured falls below your commanded. Like the pic I attached.

That is exactly what it is supposed to do within a given allowance .. that means nothing much whatsoever.

here is why: http://rawze.com/forums/showthread.php?t...6#pid75536

[Rockinbexpress]

(04-23-2023 )Rawze Wrote:  

(04-23-2023 )Rockinbexpress Wrote:  pressure keeps dropping below commanded then ramps up and pump
...

and...

(04-23-2023 )Rockinbexpress Wrote:  ... In the meantime graph your commanded and measured fuel pressure and see if your measured falls below your commanded. Like the pic I attached.

That is exactly what it is supposed to do within a given allowance .. that means nothing much whatsoever.

here is why: http://rawze.com/forums/showthread.php?t...6#pid75536

What is within reason? That's the question. How many psi should it droop below commanded pressure?

[Rawze]

(04-24-2023 )Rockinbexpress Wrote:  ..
What is within reason? That's the question. How many psi should it droop below commanded pressure?

That is set in the programming and the allowance is set differently for various tier engines.

here are just a few of these settings that are related to your question ...


*_APC_hp_BankDevThreshold {individual cylinder bank deviation allowance}

*_APC_hp_ImaTrimEnTol {steady state tolerance}

*_APC_hp_MaxErrorDev {above/below target pressure tolerance}

*_APC_hp_MdvControlTol {undershoot tolerance}

*_QTD_hp_MaxInjPressDrop {Max allowed drop in pressure for one injector firing event before a bad injector is detected}
=============

Basicaly, if your engine was going out of its allowed tolerance, then it would be throwing a fuel pressure or other related fault of some sort.