Hard to start
 

I've been experiencing an issue with starting. When I go to start my '99 with the air dog 100, it sometimes does/doesn't start. Usually if I pull the key back and hit it a second time it fires right up. I brought it to one mechanic that replace the air dog lift pump. I got the truck back and I have the same issue. I brought it to another mechanic and he couldn't get it to act up. Well it certainly does it for me. Can anybody help? Could it be the ignition switch?

only when cold starting? does it have the same problem when its warm?

It makes no difference if its warm or cold

I have a fass t4 on my truck, I try to listen to hear it pump before I start the truck, is the airdog not pumping when you turn the ignition?

first thing you need to do is check your fuel pressure and be sure you are getting at LEAST 7psi while cranking the engine over.

7psi is the rated cranking pressure for these trucks and 10psi+ is the rated operating pressure once the engine is running.

I need to get gauge cluster I just haven't yet, im confident im getting proper fuel pressure with my truck, I was only curious because when i'm out doing errand's and the truck is at operating temperature and I turn it off and come back(5-20 minutes later) it wont start. if I use the gas peddle it'll start instantly, is that normal?

no. definitely not normal. being computer controlled and throttle being nothing more than a cable pulling a spring loaded sensor, you got some kind of electronic issue in either the vp44 computer, or the ECM.

cold or hot it should fire off right away without any kind of long cranking.

vp44s are freaks in the diesel world and known for ridiculously fast starts.

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some light reading for you: VP44 Diagnostic

i had the same issue after replacing my vp44. long start or no start when hot. one way to check and verify that your vp44 is the problem is dump cold water on vp when you cant get it started aftering running engine and getting everything warm. if it fires right up after doing this test you will be in need of a injection pump.