BlackSmoke55

i was headed toward the pass from Seattle to north central WA and my fass lift pump quit. pulled it off in a parking lot and took it apart on my tailgate. after looking through it to find anything obvious i came up with nothing. took the motor to a electric motor shop and they tested it and it worked fine. put the pump back together and hard wired it to the battery with an inline fuse so that i could turn the pump off if i stopped for a while. it worked fine until i got home. now it will do nothing but crank. i monkeyed around with it for about an hour. bleeding my high pressure lines and my filters. i was getting 15psi before the injector pump and still nothing. out of nowhere i turned my key and it started right away. i didn't shut it off till i got back to my house. (i was stuck at a store about 15 miles away.) ran fine the whole time. got home and cycled the key. and it shut off and turned on fine 3 times in a row. went inside for 30 minutes and came out and tried it again and it just cranked. I got frustrated and just left it there for the night. im gonna go see if i can find anything but any insight would be awesome. im thinking it has to do with air in my system. (i took the pump off and might have not gotten a good seal on one of my connections putting it back on.)

Tallguy67

I see this is your first post, welcome to DTR.

Before we getto complicated stuff, let's start with the easy stuff like 'Do you have any diagnostic trouble codes'?

If you start to read this forum you are going to automatically assume that your VP44 (injection pump) has gone bye bye. Before you just assume that, here is a link to a site with some of the best VP44 diagnostic procedures you will find.

Blue Chip Diesel

BlackSmoke55

thanks for writing back on here. i went out and started looking for patterns that i could follow to my problem and the end result ended up being that my inj. pump wouldnt run right with 14 pounds of pressure behind it. and because my pump was hardwired with a fuse, i would put the fuse in and try to start it. if i primed it, pulled the fuse, started it and put the fuse back in real quick it would start with no problems. i searched out the stock lift pump wire and tapped into it.

DIESELWRKS

what type of fass pump is it? with filters or not. have you traced all of the wire/harness with the fass?
double check the relay in the harness is clean and seated in the connection.
the power wires pos and neg are connecting good.

VADSLRAM

No codes or CEL?
Mine is acting like that and it is showing the CEL. Code says crank position sensor.
I will turn the key and the LP cycles for about a second then stops, but no starting no matter how long I crank it. If I wait for the right phase of the moon or cosmic vortex(no clue how long or why) it will start normal.