Low Fuel Warning Light

On Wed, 17 Jan 2007 22:11:42 -0600, Ford Tech rearranged some electrons to form:

Hey, you finally said something that was correct.

Only when you get called on the carpet.

Ok ANYONE with questions as to why you shouldn't run your tank low on your vehicle should read Chapter 17 of the book called: "Medum/Heavy Duty Truck Engines, Fuel, & Computerized Management Systems" "1st Edition published in 1999" "2nd Edition published in 2004" Authored by Sean Bennett

If you dont have a copy in your local library, see if your library has a loaner program. They should be able to get it through this program, as I know the Pittsburg State University Technical Library is involved in this program. Also 2nd Edition has the EXACT same information in Chpt 17, as the

1st Edition. The page numbers will vary as information in OTHER sections of the book have changed with different systems being introduced in to the market.

Chapter 17 deals with "Diesel Fuel and Alternates". It has a section in this chapter that deals with "Fuel Storage, Fuel Deterioration, and Performance".

The section in the book that I have referred you to, only REINFORCES the points that I have made to you in this forum about why you should NOT run your fuel tank low. It is NOT an "old wives tale", infact it includes a tech tip (both editions) that states, "It is good practice to keep fuel tanks FULL. This keeps moisture-laden air out of the tanks."

It further into the section covers points that deal with hot weather, and overheating of the fuel. As to Mr. Cuda's question about where the fuel rail is, most diesel engines run the fuel rail inside the head via bored passages. The only exception that I can think ok (not saying its the only one, but just the only one I can pull off the top of my head) is the Cummins B Series 5.9L. Now remember I am talking about COMMON RAIL fuel injection systems on diesel engines. I am not talking about gear driven pumps that run an individual line to each injector straight from the pump. Those kinds of systems are so outdated its not even funny. I just checked FMC DEALER and the 6.4L will continue using the HEUI system as well, only addition will be the fuel cooler added to the fuel return line on top of the engine. Dont question my dedication to the trade. I have the knowledge, and the info.

I discussed Mr. AARCUDA69062's scenario (the pullin the trailer with a gallon of fuel in the tank), with a very good friend of mine that is a master diesel/auto tech, and a DIESEL instructor at one of the top 4 schools in the U.S. for Diesel techs (Pittsburg State University), as well as a part-time advance trouble shooter for a local Freightliner dealership. He only reinforced my thoughts on the fuel tank acting as a "heat exchanger" for the fuel returning from the heads. He further went on to say that I was probably wrong on the temperature of the fuel left in the tank, saying "it was probably hotter than that" when I said that it was probably atleast

150*F in the tank. Now, if the fuel tank is acting as a "heat exchanger" for the fuel, and your fuel pump has to pump fuel in excess of 150*F, then the effective temperature of the whole fuel pump is increased above that due to the amount of heat created by the windings in the pump, and the friction of the fuel against the parts of the pump (that would be fluid friction, hydraulics 101), and temp of the pump is probably running around 200*F. This excess heating of the pump, if done often enough, can and will cause premature failure of the fuel pump, and can cause premature wear of the injectors.

So, by telling someone that it does NO HARM WHAT-SO-EVER to run their tank to empty before refilling every time, is COMPLETELY ludicris. It DOES harm the system, and CAN change the properties of the fuel in the system.

FORD TECH

Forgot to include this- ISBN 0-8273-8574-9, that is for the hardcover edition, it doesnt give me one for the softcover edition.