Disappearing boost

[2Farr]

I have a 1999 ram 3500 4wd quad cab auto, with the 5.9 24v engine. The engine is totaly except for a Banks 4" exhaust and waste gate actuator.Around town or flat road if you mash the fuel pedal It will spin to 3200 and shift. Boost is at 32 lbs and egt is at 880.
Now for the problem. When I drive up a hill of 6% with 300lbs in the bed, max egt 880 max boost 22lbs and the truck just stops accelerating at 70mph up the five mile hill. I'm thinking mabe a air leak in fuel line?

 

[DavidC]

What is your fuel pressure ?. Stock lift pump or modified ?. Was it changed to the in tank pump ?.

 

[2Farr]

New tank pump 2 years ago. New injector pump 4 years ago. I have a Fass pump off my 98 I will be putting on soon. Haven't checked fuel pressure at injector pump yet.

 

[DavidC]

To use that fass your going to have to remove that in tank pump by using the stock module or a replacement from geno's or use a draw straw. It would probably not be sucking air in the fuel line as you are pushing fuel from the tank with that pump. I would pick up one or two mechanical fuel pressure gauges with enough hose to reach from your fuel canister to somewhere around your windshield so you can see what is happening. You really need a permanent gauge with that VP. Tap the mechanicals into the brass plugs on the filter top. The furthest from the cab is post filter and the other pre filter.

 

[2Farr]

Looks like I better be fast with installing my Fass pump.
This is at idling. It is the same from both ports. Changed filter last week.

 

[DavidC]

That port is after the filter, did you try the other one. I have heard the in tank has less pressure than the original but that's all I know of it.

 

[Joe Mc]

Scrap the in-tank, Vulcan Draw Straw, put the FASS on it and move on. Remember you can't just put the FASS on as it'll still be trying to pull thru the in-tank.

 

[Bob4x4]

If your truck is totally stock it will derate above stock boost levels.It should also trip a cel for over boost.Is there a boost fooler installed?

 

[2Farr]

There is a boost fooler installed.
It now has a Fass pump with a tank sump installed.
It now has 21 lbs at the injector pump.
Test to follow.

 

[2Farr]

Did the hill test today. Held 21 lbs of fuel pressure and reached 32 lbs of boost. The engine pulled well up to 3k in od lock up.
Think it's fixed.