Engine/Transmission (1994 - 1998) 12 valve fuel heater problem and questins

[vaicase]

my 1994 fuel heater does not work. it is getting power but no heat. my question is do i really need it?this is my second winter with the truck and it starts good. i have been told it is also a prefilter. and very expensive to replace and is not really needed. i took my stock fuel filter and housing and replaced it with a davco 382 fuel processer. it has a 5micron filter. works great engine even sound quieter. so can i just bypass the heater housing?thanks

 

[Joe G.]

The fuel heater is worthless even when it works. The heater which looks like a hocky puck can be removed from the fuel heater/pre-filter assembly. Keeping the pre-filter is a good idea because it protects the lift pump from crud. Email me at -- email address removed -- for my 12 valve fuel supply system write up, how it works and how to fix it. There is information on how the fuel heater fails and how to remove it.

 

[Fordiesel69]

Why do fuel heaters fail so often? Every diesel I owned, the unit was electrically open. Both fords, my friends chevy 6. 2, and I am sure my dodge is too.

 

[Joe G.]

The fuel heater used for a 12 valve Cummins in our trucks is actually worthless. It is impossible for it to help start because there is about a quart of fuel between the fuel heater and the injectors. There is no way that hot fuel can get from the fuel heater to the injectors until the engine has been running a while. The batteries would run down long before hot fuel could get there at cranking speed. While the hot fuel is being moved, it is being cooled down by cold fuel, cold filter, cold fuel, cold injection pump, etc, etc, etc... .



If it fails and causes an air leak the air leak is really hard to find because it is in a crazy place, the connection to the wireing harness.

 

[Vaughn MacKenzie]

This link has prefilter info
Fuel Pre-Filter Cleaning on Ram/Cummins