Engine/Transmission (1994 - 1998) Fuel Heater Melted

[Hummin Cummins]

I was cleaning my strainer the other night and noticed my fuel heater had vibrated loose also. The retainer was barely finger tight. Its off now, been below zero and no problems.



Chris

 

[TSeran]

So does any one know why all these HEATER SENSORS are burning / melting out??

I found mine like this,,cause I had that pain in the BUTT fuel leak down there !!!!

Also I found the SOFT spring also broke,, does any one know what that one really does,,NOt the stiff one .



THANKS



Mike In Maine

I plugged my 1995 12v Cummins in for the first time the other day to offset the 7 degree temperature.



The truck didn't start even after leaving it plugged in forever (as in a couple of days).



Yesterday, with the truck plugged in for a few hours, I started it after turning it over several times. The little dash light doesn't come on when it is "warm" from the plugin. Seemed to all be well except for the fuel leak from somewhere under the fuel filter. Too nice a day to waste on fixing the truck (been freezing here for some time allthough today should be in the low 60's I hope) so I parked it and fired up the Subaru.

What did I fry? or is this coincidental that the leak, which I think was much smaller in days past and hardly noticeable? After reading some of the posts, yours in particular, I have the feeling I fried something.

Can you leave it plugged in all the time?

Phew!

 

[Joe G.]

The fuel heater is a different gadget than the plug in block heater.

 

[GROBBINS]

Hey Vaughn, the Dodge truck is one of the only B5. 9 12V applications using the prestrainer/heater. Every heavy truck/motorhome I have worked on has never had a fuel heater installed. In fact, most of them don't even have grid heaters! No fuel problems or hard starting due to cold either...

Yes, because who goes out and fires up the motorhome when its neg. degrees out. Or what trucker turns off the engine when it has to be started in the morning. I have been battling cold starts every other year here in WI. I am on my second heater relay, in 2yrs. I have never added any additative either. Once the truck is running, I'll take it anywhere. #2 only. I want to get down to the bottom of (why) these heaters are burning up. I like my truck to be as reliable as possible, and if the upgraded part is going to save me the time and expense of additatives then sign me up!

 

[Cooker]

Yes, because who goes out and fires up the motorhome when its neg. degrees out. Or what trucker turns off the engine when it has to be started in the morning.

Not all of these truck are OTR trucks but local rigs that get shut down every night and restarted again every morning.



Also these engines are found on various equipment and there is not a fuel heater on those applications either. We had a couple that did not have a fuel heater or a grid heater and these would need some encouragement to start at times. The ones with grid heaters never let us down.

 

[Joe G.]

Grobbins,



Please explain to me how the fuel heater can help starting. There is about a quart of diesel between the fuel heater and the injectors. Most of that is in the fuel filter. So no matter what, you are starting with cold fuel. Even if the fuel heater really gets the fuel hot it can't get to the injectors before the truck starts or before the batteries are run down trying to start it. One thing that is happening is all that cold fuel, cold filter, cold steel lines, and cold injection pump are cooling off the heated fuel from the heater before it gets to the injectors. The thing may be some help after the engine has run awhile, but it sure does not help starting.

 

[Cooker]

I agree with Joe. This idea has been hashed about many times before.

 

[GROBBINS]

Joe, in that case, every engine that is running straight #2 in the winter without additives has trouble starting because of the cold fuel, heater or not. Is that correct?

 

[Joe G.]

You can't jump to conclusions like that. That kind of argument is based on an assumption that is not true. There are a lot of other Cummins 5. 9 applications (as noted in some posts above) that start just fine with no fuel heater. There are also a bunch of these trucks running around with an inop heater that didn't manage to cause a leak when the heater quit. In fact, when mine failed I didn't have any symptoms until I pulled the electrical plug out when I was doing something else. Then the truck would not start. Before that it ran just fine with an inop heater.



Mine starts just fine in very cold weather when we go to Utah in the winter. I don't even let the grid heaters run most of the time because I forget it. Just twist the key and it starts. Some rock and roll when I do that, but it starts.



The heater is worthless for starting. If you want a demonstration of how long it takes fuel to get from fuel heat to the injection pump change filters. Open the output bleed screw. Run the starter until the filter fills up. That's is about how long it takes to get heated fuel from the lift pump to the injection pump.

 

[Cooker]

One other thing that is worth mentioning. Many people running the FASS systems do away with the OEM fuel heater. I don't hear any of them complaining, myself included. It was 7 below here the other night, the truck sat unplugged for 8 hours and it fired up just fine without a fuel heater.

 

[PKemp]

Joe G; Grobbins:

I run a very large, heavy diesel repair facility and an over the road trucking company. We see a lot of Fedex and UPS delivery trucks that have cummins B5. 9L engines from 1993 thru 1998. None of them have fuel heaters or even pre-filters. This set up has a Ford chassis in the UPS and Fedex 5 ton delivery trucks. No pre-filter or fuel heater.

My Brother works as the shop foreman in a UPS maintenance facility in Buffalo, NY. He and I have been discussing this thread. All of thier pre 2000 trucks have the cummins B5. 9L engine also without the "Dodge" pre filter/heater assembly at all in a Ford chassis. They run #2 throughout the year (even this winter) no additives. Sometimes starting is a little "ratttttly" but still successful. They use thier block heaters and have heater grids on the air intakes like the dodge's.

I must support Joe G. The fuel heater and even the pre filter seem to have no significant purpose other than a source of revenue for Dodge as a replacement part.

If you are really concerned, just plug in your block heater and use an occaisonal additive. Amen I say Joe G.

 

[GROBBINS]

PKemp, Thank you for the input, you also Joe G. Very useful information.

 

[Joe G.]

Grobbins,



If you are having cold start problems it may be that your idle is a little on the low side. You might try giving it a little pedal to help it start in cold weather. I do that all the time anyway. I get in the truck and twist the key while pushing down on the pedal. I never wait for the grid heater. When I do that in Utah it scares my son-in-law because of the banging around in the engine room. It's a good thing these things have strong motor mounts.

 

[upsyes]

Help!!

Can someone please tell me what size allen head the adapter takes so that I can remove the fuel pre-heater assembly on my 97 dodge? Thanks alot!Eric

 

[hsmith]

Believe it is 8mm, 5/16, are the same size.

 

[upsyes]

Thanks alot! Worked fine. It's just VERY touchy getting it in when working from up above. Feels like you are tilting the wrench handle back toward the engine for the wrench to slide in the hole.

 

[kenny61]

My heater fried many years ago when the pump went dry due to the rubber line cracking up by the block (hard start problem) I disconected the wire and never worried about it again. Truck always starts even in single digits. sometimes the fuel gels a little depending on the quality of fuel from the pump and it wont go over 15mph. 5 minutes of a high idle usually gets it all flowing again... .