Cummins won't start when hot
 

The truck runs great and starts perfect when cool, but run it for a few minutes and it won't start once I shut it down.

I have replaced 2 lift pumps, 2 injector pumps, MAP sensor, and fuel tank pick up and filter, the only thing accomplished is messing up the fuel guage. Now I run out of fuel at a 1/2 tank.

A match and 20 gallons of gas are starting to sound good and cheaper.:argh:

** Please post questions in the correct forum **



1) Do you have a fuel pressure guage - absolute must on a 24V. Truck shouldnt leave your driveway without it.

2) Stock lift pumps are junk - dont waste your money on them

3) Have you scanned for codes?

No guage, but will get one.
Code machine lights like a christmas tree, but did not get them from the mech

Hard starts when warm are one of the classic signs of VP-44 failure. Notice and white smoke (when warm)??

Need codes if you are looking for advice. Good luck.

need to check fuel pressure

codes are going to be a must. it sounds like the vp has gone bad. throw the stock lift pump away and get an airdog and a pressure gauge.

Hard hot starts are the classic 2nd step of the vp44 - first step stock lift pump fails then without pressure guage - the injector pump vp44 starts hard starting then soon wont start at all. Once you put on guage get an airdog or fass and you will be a happy man. BTW if you need to change out the vp44 (you will) I have the tool to remove it and will loan it too you if you promise to return it. It is really kinda fun to do but can be stressful too. Also the screen on the fuel tank pickup bottom is really restrictive - engineer something better- I used a much larger heavier duty screen after the aftermarket lift pump install.

It was the VP44. Thanks all. I don't know why or how I got 2 bad ones in a row, but I know why I have a new mechanic.

good to hear. glad you got the beast running

Did you order a fuel pressure guage?