Engine/Transmission (1998.5 - 2002) Correct Fuel PSI on a 1999

[jmos4]

Hi,



I have my first Diesel and was told about keeping a eye on the Fuel PSI, but have read a lot of different numbers on several sites.



I have a 1999 with a Hot Rod VP pump and a stock replacement in take lift pump and a aux lift pump on the frame rail



with the stock replacement PSI will read about 7psi at idle if I get on it it will go down to 2psi



with both pumps on it will be around 12 psi and go down to 8 or 9psi win I get on it though after running both for a while it starts to bounce from 5-12psi and then I shut off the aux and ti stabilizes at 7 again



so what psi should I be trying to maintain?

should i be getting a better lift pump?

should I use both at the same time or only the stock replacement?



Thanks for info,

 

[DavidC]

Mine stock except the fueling box, 13 at idle 10-11 at 65 -70 cruising and 9 full throttle. If it gets down to 5 I would get worried. Are your readings pre or post filter?. Stock filter?. When my readings were low it was on the suction side as the in tank screen was covered in a vaseline type substance. That screen has been gone for a while now and an in line fleetguard is installed now.



Dave

 

[DACoffman]

mine runs like davids if mine hit 5psi i'd be changing pumps on side of road,keep one under back seat.

 

[ALepley]

That sounds really low. I would definately have it checked out. Those HotRod VP's are not cheap. Those pumps especially need good pressure consistantly. I'd check your pumps. Get rid of them both and go with a Fass System or Airdog.

 

[fox]

Hi,



I have my first Diesel and was told about keeping a eye on the Fuel PSI, but have read a lot of different numbers on several sites.



I have a 1999 with a Hot Rod VP pump and a stock replacement in take lift pump and a aux lift pump on the frame rail



with the stock replacement PSI will read about 7psi at idle if I get on it it will go down to 2psi



with both pumps on it will be around 12 psi and go down to 8 or 9psi win I get on it though after running both for a while it starts to bounce from 5-12psi and then I shut off the aux and ti stabilizes at 7 again



so what psi should I be trying to maintain?

should i be getting a better lift pump?

should I use both at the same time or only the stock replacement?



Thanks for info,

5-8 is the lowest you should allow. 15 is a good number for steady state running.

If the pressure drops, there will be very little excess to go thru the pump to cool it.

The factory method is poor. both in quality and placement. Before I got smart I bought several NEW in BOX carters and two were dead. RIGHT OUT OF THE BOX.

 

[jmos4]

Thanks for the replies all,



Now which aftermarket pump and why?



FASS or Air Dog



is one better, quality, technical help, warranty dealings



I am going to check it out this weekend to see what is up and what I really have as there is 2 pumps and want to install a system with the least amount to work, like it will be a big plus not to have to pull the tank as I think I have a Draw straw for the one external pump I have and also one in the tank



Thanks again for the info,