Archived Acrid smoke, then, "It's dead, Jim..."

[CJ Johansson]

98 12V



Well, the mighty Cummins died yesterday morning. Smoke from the engine compartment, then the engine quit running.



Once I got to looking at it, the smoke was coming from the diesel fuel heater in the pre-filter. Looks like it's toast. As to why the engine quit, I'm not completely sure.



I tried pumping the primer button with the bleed screw open, I got some foam, but not the regular flow of fuel. With the pre-filter bowl removed, pumping doesn't seem to make the expected mess, cranking the engine doesn't cause fuel to pour out either. So, I'm guessing the mechanical lift pump died.



As for the fuel heater, I'm guessing that when it was left high and dry due to lack of fuel, it overheated and burned up.



So, any other ideas out there? Has anyone changed/rebuilt a lift pump? Do you have to change the whole thing, or can it be rebuilt? How the heck do you get at it to work on it? How do you replace the fuel heater? (I got the part out that looks like a plug, but there's another wire going to the top of the pre-screen that doesn't appear to unplug).



Thanks,

-cj

 

[Sled Puller]

Just guessing here, I see you are in Idaho, how cold was it?

Could a bad batch of fuel gelled up and starved the engine for fuel?



Most of the time on 12 valves, the pusher pump just gets weaker and weaker. I guess it could just quit.



Change the whole thing, I doubt it is worth rebiulding. Most any auto parts stores are carrying them now, on the shelf. What does that tell you? Lucky us.



Stand on your head, or come from down below, both suck.

I don't know about the heater.

 

[CJ Johansson]

Gelling

No, I don't think the fuel gelled, it was a balmy 28 degrees yesterday morning... Most of the stations around here pump winter blended fuel this time of year...



-cj

 

[Sled Puller]

Too bad, easier to fix that than a lift pump!

Gene

 

[Joseph Donnelly]

To change the lift pump:

I go from the top, use a medium extension (about 6") and 10 mm 6 point socket on a long handled 3/8 drive ratchet to remove the lift pump bolts. One is to the rear, the other is at the front of the pump and clearance to the fuel preheater assembly is snug. This also will enable you to remove that part to inspect/replace it, if you remove the feed line instead of the elbow hose (below).



First, remove the rubber elbow hose from the pump and the 12 mm headed banjo bolt at the fuel filter. Leave the line on the pump as a "handle". Instead of the elbow, you can remove the fuel feed line from the preheater if you want to take it off too.



If you are careful you can probably reuse the fuel pump gaskets, they are the same size as Chevy etc. but Cummins is better with apparently rubber coated steel.



I'd reuse the old plunger as it is worn in to the camshaft lobe, unless it is in bad shape. Put a bit of cam lube (Crane etc. ) on the ends--the plunger can be pulled out of the pump, oil it before reinserting.



You will get needed clearance to reach back to the pump by removing the steel boost air tube coming from the intercooler to the air intake horn. At the bottom, the easiest is to take the rubber boot off the intercooler; at the top I take it off the air horn. 7/16" or 11 mm socket on the band clamps.

 

[CJ Johansson]

Thanks Joe!

Well, that's great info! From searching the forums, I found the part numbers for the pump & gaskets. Now for the good part (I hope)...



I called the stealer, uh, dealer, they said the transfer pump is covered under warranty! So, hopefully, if that's really what the problem is, they'll fix it for free. Now, I'd rather have the local Cummins guys do it, but they say you have to go through Dodge for warranty.



And, I opened the AFC cover, so hopefully this won't affect warranty work on the lift pump Anyone know??



-cj

 

[Don M]

CJ,



make dern sure the Cummins or Dodge guys use the lubricant that Joe was talking about. I have heard of cases were the new lift pump plunger or even using the old one was not lubed before installation and the cam was worn down causing lift pump to not work properly.



The lift pumps can be rebuilt easily. Since yours is covered, youll get a new one.



Tinkering with the AFC can cause a warranty problem. Dont tell 'em you did.



Let us know what happened.



Don~

 

[Joseph Donnelly]

The lift pump has nothing to do with your afc adjustments. If your dealer has a history of being unfair, you can avoid their suspicious nature with a new breakoff screw and a spray can of Cummins Titanium black paint, #3824514.

 

[CJ Johansson]

Originally posted by Joseph Donnelly

The lift pump has nothing to do with your afc adjustments. If your dealer has a history of being unfair, you can avoid their suspicious nature with a new breakoff screw and a spray can of Cummins Titanium black paint, #3824514.

Thanks Joe, I haven't heard anything negative about my dealer with respect to mods, of course, I rarely go there. They didn't say a word about my custom 4" exhaust with dual stacks the last time I was there, so maybe they don't care.



I won't need a breakoff screw since I only removed the plug covering the star wheel. When I did it, I noticed some bright yellow paint under the "black" paint (I assume this is to make tampering more noticable). Looked at it yesterday, the dirt seems to have obscured the yellow so the only thing that shows is the paint being scratched inside the hex socket hole. I doubt anyone will pay attention to it. I might pick up some paint though...



So far, the truck is still sitting at home. I'm currently trying to figure out how to get it to the dealer. I'm about 40 miles away, 4 miles up a gravel road with the last half mile 8" deep mud up a 12% grade (ya gotta drive on it early in the AM before it melts, or late at night). I've got a 16 ft. flatbed trailer it'll fit on (how embarrasing, I'll have to pull it with my wife's Ford ). But, since the Dodge won't go, I'm not exactly sure how I'm gonna get it up the ramps and on to the trailer.



-cj

 

[RustyJC]

Originally posted by CJ Johansson

So far, the truck is still sitting at home. I'm currently trying to figure out how to get it to the dealer. I've got a 16 ft. flatbed trailer it'll fit on. But, since the Dodge won't go, I'm not exactly sure how I'm gonna get it up the ramps and on to the trailer.

I see by your signature you have a John Deere. Why not pull the truck onto the trailer from the front with the John Deere?



Rusty

 

[CJ Johansson]

It's alive again!

Well, after talking to the stealer again, they were unwilling to assure me that it would be covered under warranty. All they would say was, "Well, it should be, but we won't know until we get it in and type the numbers into the computer". They wouldn't do anything over the phone, even if I gave them my VIN, etc.



Now, I can understand them not trusting my diagnosis, but you'd think they could tell me if the lift pump was covered in the event that it was really dead. I decided it wasn't worth the gamble since I'm sure they'd charge me labor to diagnose what I knew was wrong.



So, off to get parts. A friend who repairs big trucks for a local outfit said the local Kenworth place is cheaper then Cummins. I called Cummins, a new lift pump was 165. 00, the Kenworth folks said they'd have to go down the street to Cummins to pick it up, but it'd be 149. 83. OK, I know who to buy parts from now!



Anyway, I'll write up a more detailed description of how the change is done on the 12V forum, probably Tuesday. But, thanks to all the pointers from Joe Donnely, it went pretty smoothly, took about 4 hours working outside in the snow (on the ground and comming down, it's still coming, around a foot so far, I'm glad I did it yesterday when we only got 3 inches!).



First, I'd add to Joe's instructions, remove the fuel filter canister. It makes a huge difference in access and ability to see what you're doing! Taking the intercooler pipe off is a huge help, it gives you a lot of room, I'm kinda considering doing that every time I change the fuel filter, maybe not though, getting the hose back on the bottom of the intercoller is a bit tough.



I couldn't use the outlet pipe from the pump to the filter as a handle as Joe suggested since the inlet pipe (from the tank) was run in front of this one. I had to remove the outlet pipe from the pump first. You have to remove the inlet while you're down there anyway, so one more fitting is not too hard.



The fuel heater is toast, literally. Plastic melted and burned. Luckily, if you take the strainer off, and use a hex wrench up in hte center, you can remove what amounts to a big hollow bolt that holds the heater in place. The strainer will fit back on without the heater perfectly. Just no heater anymore. I hope I can buy just the heating element and not the whole strainer/heater assembly. I might have to go to Cummins however, the number from Dave Fritz's site for the strainer kit came up as a whole strainer'heater on hte Kenworth guy's computer. I'll have to do some more digging on that one.



Once it was back together (getting those 2 bolts that hold the pump and strainer on started was the biggest pain in the whole project), I primed the filter with the plunger and cracked all the injector lines. I figured I'd need to do that since it ran out of fuel big time! It took a bit of cranking before fuel came out the injector lines. Tightened 'em up and cranked some more. A few sputtering starts and dies and then the Cummins roared to life like usual! I did have it hooked with jumper cables to another truck since there was nowhere near enough poser in the batteries to do all that cranking.



Well, that's about it. Thanks for all the help from everyone, especially Joe. I'm sure I would have fumbled around for hours trying to get at the pump from below without his help.



-cj

 

[Andy Perreault]

Yet another example of why a $35 a year investment in the TDR is well worth the money!!!

Glad to hear you got 'er fixed.

Andy