Help-Truck died and stranded

[Bigramguy]

Noticed some smoke coming from under hood,so i killed engine,opened hood and checked. Was coming from the two wires going into the top of a little canister down under the fuel filter. Not the fuel filter itself,but below that,it looks as if it's attached to the same bracket (just in front of) where the primer pump is. So I disconnected the connector from the harness,and fired it up. No more smoke,and it ran ok so i carried on and it quit about a min later and would not restart. It would sputter and cough a bit,but now nothing. Tried priming it (from the air bleed on filter outlet) and all i get is frothy fuel just full of air. Thought maybe it was out of gas (damn broken sending unit),but have put in 5 gals,and still nothing. Pulled fuel line coming from tank (at rear of intake) and none came out,but i could siphon it up with a vac pump. Could this little fire at what i think is the fuel heater have burned a hole into it and caused an air leak ? I have no fuel leakage there though. I can only see one line going into it (from the tank),and none coming out. I assume it must feed through some internal passage to the primer,and then i can see another large line coming back up the the fuel filter. I have also pulled this one off,and get no fuel when i try to prime it. There is also a large rubber line that goes from the top of this little canister,over to the primer. I checked for fuel and any sort of pressure there and there is none,although i think it is not fuel system line. Now i'm stuck. Is there any way to get this thing bypassed to see if that is the problem,and to get it back to my shop ? Which brings up one more question,where is the lfit pump ?I am assuming it is all part of the primer assy ? So if i did bypass it it would probably not work,as i am bypassing the lift pump also ? Is this correct ? Please help. Thanks in advance.

 

[HEMI®Dart]

Bigram,



Your fuel heater is coming on in 80° weather too?



Check your Pre-Filter. If its clogged, you won't be able to draw fuel from the tank to the lift pump.



See here: http://dodgeram.org/tech/dsl/filter/pre-filt_clean.htm





The primer is part of the lift pump. The lift pump will draw fuel from the (canister) heater/ pre-filter, then send it up to the fuel filter head. Your lift pump could be shot. Usally they leak before they go though.

 

[Joe G.]

The fuel heater, pre-filter, priming pump, and lift pump are all in the same unit. I suspect that the cause of the problem is a stuck fuel heater relay. If the fire was pretty hot it could have plugged up something in the unit or burnt up an O-ring so it doesn't work. If that is the case you may have to take the whole mess apart. I think Swamp Rat just went thru his and maybe can make a few suggestions about taking it apart.

 

[Bigramguy]

Thanks for the info guys. If you follow the link that Hemi posted,and look at the second picture,you can see an electrical plug going into the top of the pre filter\heater unit. That is where my problem is and it now is no longer there,just a black hole,after it burnt up. There are two little T15 torx screws which seem to hold the unit in the prefilter,and i'm trying to get them out to see if i can see if it is leaking. Does anyone know if this little heater is available separatly from cummins ? I think the lift pump is OK,because if i crank it with the bleeder screw open it does pump out some stuff (very frothy fuel),but it's just full of air,so it must be sucking it in where the fuel heater burnt up. Thanks again

 

[Bigramguy]

Another update - Got the little screws holding the fuel heater in place,and it does not actually go into the fuel. It is just a small round unit,like a watch battery,which heats up the top of the canister. It just sits in a recess,but does not go through into the fuel,so no chance of it leaking air. So it must be something else. I have the fuel line off at the back of the manifold and when I try to prime it,it is not sucking anything up at all,so i must have either an air leak somewhere else between that line and the lift pump assy,or the lift\primer pump assy is bad. Any other ideas before i go get a new lift pump assy ?

 

[HEMI®Dart]

BigRam,



I think those 2 torx screws attach the Fuel Temperature Sensor to the assembly. You might as well pull that too. After the pre-filter bowl is off, there should be an allen bolt holding the heater assembly to the housing. Loosen this and the heating element should drop out. See what it looks like. If in doubt, replace it.



The Cummins or Dodge dealer should have one in stock.



They need to put a fuse or a circut breaker in the fuel heater wiring. This would have never gone this far.



There is an square cut O-Ring on top of the fuel heater element. You will see it once you drop the heating assembly (allen screw) See what that looks like. Maybe its melted? You could be sucking air in thru there. ?

 

[Bigramguy]

So i guess it wasn't the fuel heater,as it is the upper most plug (the one with the torx screws) that burnt up. I haven't dropped the pre-filter yet,but i guess i will have too. Does anyone know if this is covered under the Chrysler\Cummins engine warranty ? My basic warranty is up,but i still have the engine warranty left,so if it is i may just tow it straight to the dealer,as they will just probably replace it all if it is covered.

 

[HEMI®Dart]

Ram, I think that is the thermostat for the fuel heater( torx screws). Try checking the o-ring on top of the heater. That very well could be the problem. You still have a problem with your fuel heater if the t-stat burned up.



It WON'T be covered under warranty. Unless you are real tight with your dealer, then maybe

 

[Bigramguy]

Well,you are right,the problem is the fuel heater,not the temp sensor. The temp sensor (on top) was the one that burnt up,but i just found the lower plug,which would be the heater,is sucking air through the electrical plug. Now that i have it unplugged i can hear it. If i stick my finger over it,and pump the primer,she will now push fuel up to the filter. I will try to take the plug,and fill it with silcone and let it set up for a few hours and that should get me to my shop so i can haul it all apart. Thanks again to everyone who replied. It probably saved me a pretty hefty tow,and a lot of headaches. I will post another reply to let you know when i get it fixed,as to just what all it took,and maybe there is a way to prevent this from happening again as it was a PITA doing all this on the side of the road. Thank god for my laptop and the TDR !!



Cheers



Chris

 

[swamp rat]

Looks like I made it in here a tad too late to offer any assistance.

Chris I can feel for ya as just doing it in my front yard is PITA. I can only imagine how bad it must be to have to do it on the side of the road. When you get the opportunity, be sure to check the short fuel line between the filter/heater assembly and the lift pump for deterioration. If it looks even the least bit cracked and dried out, replace it as well. Mine was in good shape, but if it ever springs a leak, you will probably have the same symptoms you just experienced minus the smoke. Good luck and be sure to update us when all is well again.