Engine/Transmission (1998.5 - 2002) Lift Pump wireing.

[Bandit2]

Installed a new LP at 79k. New pump came with the pig tail. Pump came from Cummings dealer. I have a mechanical fuel preassure gauge that seems too work fine. Now after around 2k the new pump is acting up. Some times it is pumping 14lb. ,sometimes 7lb. The terminals at the pump have been checked and greased with elec. grease. No help.

My question -is there some place foward of the pigtails where I can check the elect. connections? Or maybe I just got a bad pump?

Any help would be great!

99 24 valve Dick Reynolds

 

[bmoeller]

If you can, I'd check the voltage to the pump to see if it drops, when the PSI does. Could be an electrical problem.

 

[Bob4x4]

Remember that signal to the lift pump is pwm not a constant. If you want to see a constant battery voltage to the the pump use a relay,with the ecm triggering it.



Bob

 

[rweis]

I just had a new lp installed by DC and after 2k it is not going "unnnnnnnun unnnnun". Thankfully I have put in a RASP and have to fix the lp as a backup.



I put dielectric grease the whole bit. I did not run a relay, but I guess I will now. I have learned not to trust the DC lp AT ALL. DC did replace the VP that the lp killed though.



Bob Weis

 

[Bandit2]

Bob4x4

I think from what you told me, that the pump is not expected to put out full preassure all the time? That I did not know. As I am not very sharp about electronics, would you explain PWM? Don't know what the abbreveation means. Allso,ECM which I guess means, engine controll module. where would I find the ECM on the engine?

This morning the pump was pumping 14-6lbs.

Thanks for all your help. Dick R

 

[Bob4x4]

Pwm is pulse width modulation,to make it real basic the power is turned on and off to vary voltage rather than supply less voltage all the time. The ECM is on the drivers side of the block,behind and below the fuel filter.



Bob