How can you tell if it is bad. I was looking over the truck yesterday and saw what looked to be a primer lever on the lift pump. I moved it a few times and it was like it was not even hooked up. Also I know a few people with the same truck I have and theirs smoke more and run a little bit better. The truck just turned 178k miles today. how much does a lift pump for a 93 cost and where can I check the fuel pressure?
thanks
DM01

 

I bought a fuel lift pump from Cummins. It was about $70.
I ended up getting high flow banjo bolts for the fuel lines from Rod at Wildcat Diesel. They have threads in the end of them to tap into with a pressure gauge.
My new pump runs at 7 PSI and just below 5 at full load.
Where have you been lately
Talk to you later

 

My lift pump is doing the same thing, it feels like its not attached to anything. Is it bad? The truck runs well and smooth but, only gets 12 mpg around town, 16 highway.

 

To test the lift pump, you will either need one of Rods tapped banjo bolt that accepts an 1/8" pipe thread at the head of the banjo or something else of the equivelant from a fuel psi test kit. You can take your readings pre or post filter. Looking at the filter housing you will see a steel line that connects on the firewall side of the fuel filter. You will need to unscrew the banjo bolt that is holding it on and screw in your test fitting. You should see 6-9 psi at idle between needle fluctuations. If you want to measure the psi post filter. Simply take out the banjo bolt in front of the filter and install your fitting. You should see the same 6-9psi reading on a good clean flowing filter.

Most signs of a lift pump failure is the priming lever like you have described. However, I have psi tested about 6 trucks that had good pressure but the priming lever was bad. The VE pump will pull its own fuel but it is very hard on the cam plate, plunger etc.

 

i thought the priming lever would only work when the engine was in a certian spot. when my lift pump went out in my 92 it missed under heavy load

 

Before you condemn the lift pump because the lever doesn't seem to do anything, turn the engine one revolution and try again. If it still doesn't feel like you're pumping something then you have a problem.

 

yes, the lift pump arm has to be in a certain spot on the cam. I ran mine for a year not knowing that it was out. When I hooked the psi gauge to it..it showed 0psi. No miss, but less top end perf.

 

so with all this said i just tore my lift pump out last and when i put it all back together it sputters and wont idle so im guessing that i should get some one to look at it to get the pump set right or how can i set it myself

 

Did you mean the Injection Pump?