Engine/Transmission (1998.5 - 2002) Easy start cold, Hard start warm??

[KevinSmith]

My truck has recently become quite hard to start after it has warmed up but if it is cold {even slightly below freezing and not plugged in} it starts on the second revolution of the engine. The engine cranks fine, there are no codes, I have a fuel pressure gauge and it drops to 0psi while cranking but always maintains 12psi while running at all speeds. It has been getting progressively worse in the last few monthes.

 

[SEmerson]

vp44 can couse that when it is going out.

 

[John - K5AWO]

I think you need a new lift pump. The fuel pressure should not be dropping to zero at any time with one exception. Doing so, will cause damage to the vp44. Ideally, there should always be a bare minimum of 5 psi. I'm happier to see at least 8 psi.

Now that said, is the zero psi that you are seeing after the initial key turn on sequence while you are waiting for the grid heaters to cycle? If so, that is normal because of the timer that turns the pump off if the engine is not running.

 

[KevinSmith]

The 0psi occers while the engine is turning over but before it has fired. Once the engine finally fires its goes back up th 12 immediatly. Lifgt pump has about 6000 miles on it.

 

[SEmerson]

I think the lift pump is fine. Hard hot starts are a common problem with a vp44 going out.

 

[MRose]

Sounds like a ruptured diaphram. Thats what i had, no codes, longer and longer cranks till you carry ether with you. I replaced the inj pump when the ether can ran out.

 

[obert]

I think the lift pump is fine. Hard hot starts are a common problem with a vp44 going out.

1) If an electric gauge, is it wired to an ign. hot wire that goes dead in start position? several accesory circuts do that.



2) Same here on the VP. Only way I could get her to fire on anything but stone cold engine was a log chain and another truck. Or park at the top of a hill. It took about 1000 rpm, a little more than the stater can muster. New VP (still under warranty, thankfuly) was the fix.

 

[NoSeeUm]

Any codes?



Jim