2nd Gen Non-Engine/Transmission warm fuel tank

[farm hand]

I have a 99 truck and when I pull with it, it some times gives me a dead pedal,

I set the APPS volt to where it needed to be and the dead pedal when away. But then it started to come back and it got worse the warmer the air temp was out side then when I was pulling a load back from Ohio it was about 60 degrees out side I had all kinds of trouble with it giving me a dead pedal, I put my hand on the fuel tank and the tank was warm to the touch, and the tank was just about full. It is only this way when I pull loads with it. Why would my fuel tank be getting warm to the touch?

 

[FourBarR]

About 70 % of the fuel pumped to the vp-44 is returned to the tank. It is used to cool the injection pump.

 

[KBrennan]

I may be all wet here but if it is getting warm in the tank it could be from the return fuel from the VP44. With that being said it would seem that the VP44 may be going out and has excessive friction going on that is causing the fuel to heat up so much. What kind of lift pump are you running? An aftermarket pump can cause the fuel to warm up. I found that to be a good thing since warm fuel atomizes better. What is the fuel pressure from the lift pump to the VP44? It should be around 15 psi. When was the last time the fuel filter was changed? If the filter is getting dirty you could have good lift pressure but loose it from the restricted filter. How many miles are on the truck? Have you been using any fuel additives that contain alcohol?

 

[fest3er]

Return fuel. Pressurizing the fuel heats it up. Running it past and through the engine heats it up. The heat dissipated from the radiator heats up the undercarriage, including the fuel tank. In time, all the fuel in the tank warms up.

 

[farm hand]

I new that the fuel was used to cool the VP44 pump but I didn't think that should make about 32 gallon of fuel warm to the touch. I have a FASS fuel pump, I have new fuel filters on it, and my fuel pressure is 15psi and my sending unit for my fuel gauge is about a foot from the VP44 pump. I have 157,399 miles on my truck and the fuel additive I use dose not have any alcohol in it. I was think that maybe the VP44 pump could be going out and would be causing the fuel to warm up more then normal but I did not want to go spend a lot of money with out getting as much input as I could get so thank you for your input.

 

[KBrennan]

With the tank and engine cold start it up and feel the return lines from the VP44 and the FASS pump. See who is the warmest. My Air Dog PF 100 has a return line that is slightly warm to the touch after running for a bit. This is caused by the pressure. When you increase pressure you increase temp. Just like on an air compressor. Something else you may want to try is check the return line temps of a friends Dodge and compare it to yours. If they are close in temp I would not worry about it. If you have or know someone that has a laser temp gauge you can use that to get a better idea of how warm it really is. Diesel burns best when it is about 90 degrees F. In the Navy we heated the fuel to 95 degrees. Since you have over 150K on the VP44 you should keep a kitty stashed away to replace it. I have heard of the stock pumps going as soon as 50K and as long as 200K+. For me I am saving for a Blue Chip VP44 plus.

 

[farm hand]

The return fuel coming from the VP44 pump is warmer then the fuel from my FASS pump,
But I went to the Blue Chip web site and the information they have up about the VP44 pump I found that my problem is the VP44 computer, and I am pretty sure the rest of the pump is worn out in side so that is what is making the fuel get warmer then it should. Thank for all your help.

 

[KBrennan]

I hear that Blue chip has one of the best VP44s available. They are pricey but you get what you pay for. I have a kitty going just to get the Blue Chip.