The other day my fass lift pump went and then while it was being shipping to me and fed ex lost my package. Now today with the snow storm i had to plow some of my accounts and i ran the truck without the lift pump so i guess the injection pump was sucking fuel. Is this real bad or is this just something that should be avoided if possible? I took it easy on the truck not trying to draw alot of fuel.

 

It definitely doesn't do the VP44 any good, but I've seen many occasions where I have replaced a lift pump that had been dead for who knows how long, and the VP44 went on to live a long happy life for years after. So don't lie awake at night worrying about it, if it's meant to keep going it'll keep going.

 

These trucks dont have vp44's-(my worst nightmare!!! Junk), they have the cp3 injection pump which is alot better pump IMO, i wouldn't keep drivin it but i don't think that you damaged it at least you can hope not

 

yeah i am not driving it anymore just had to do it for plowing it pretty crazy it ran good the whole time

 

If the CP3 can get fuel from the tank...it will pull it and its just fine operating under a vacuum....Duramax's dont have a lift pump, and the CP3 is doing all the pulling from the tank. BUT...they also have stock 1/2" fuel lines to keep the pump fed and keep restriction down and the FCA is controlled slightly different due to the vacuum draw. With that being said.....it will work, dont think you will damage anything, but just make sure all modules and such are turned off. The FASS has a built in by-pass for this thing.....

 

thanks for the response i feel better now knowing that it was ok to do, i turned my programmer off like you said so it wouldn't draw as much fuel.

 

Oops, sorry- you're right. Thought I saw 2002 in the OP's signature.