MY 5.9 has had a issue starting sometimes, will crank but no start! If i tap the injector pump with a hammer while cranking she starts. I installed a fass 150 over 5 years ago she still shows good fuel PSI while running. Also installed new injector pump at 85000 miles 4 years ago.

Edited November 11, 20159 yr by CSM

Moved your thread to the powertrain sections.  

 

 

Any codes?  White smoke when it does start?  Will it ever start without tapping the injection pump?

Error codes and fuel pressure?

Tapping the VP44 with a hammer is not a good sign.

Check engine light came on  code 1693 drove to autozone they check for codes show none! fuel Pressure is 5psi after pump cycles. No white smoke when it starts. It start 99% of the time with in 1 crank.

There is  a code stored, 1693 cannot be alone.  try another scanner.

 

5psi is too low, bosch specs 10 as the min, we like to see 14psi min.  

VERY strange issue though.  

At wide open throttle when towing i have 10psi. I have a new stock  pump should i install and see what happens

something is up, if you have a fass 150 you should have way much pressure than that.

 

But I would look at your codes again first.  Where do you use a hammer on your vp44?  

It is just a tap on the top

Anyone know how the shut down works on vp44. old cummins when you cranked the engine it pushed the shut down open when the selinode had power to it. Does the vp44 work the same way.

Do you remove the APP's sensor each time?  

 

Fuel shutoff solenoid doesn't exist in the vp44 world.   

What and where is the app sensor

I found it and no did not remove it or disconnect it

 

humm I am surprise you can get a hammer to hit the vp44 without hitting other stuff.  

 

anyways enough of my random thoughts. try another code scanner.

Its real easy to tap the vp either on the side  or the top with a long 3/8 extension

got ya

I could reach in and hit mine if I wanted to, hope it never comes to that though. You say 5 psi after the lift pump cycles, how about after the engine starts and at WOT?

It should be ZERO after the lift pump cycles. 5 PSI means there is something wrong with your gauge. I would be considering checking your gauge for accuracy.

14-20 PSI is suggest and the lowest you should see is 14 PSI at a WOT stand. 10 PSI is the book minimum but risky...