ENGINE FULL OF FUEL (UPDATE)!!!!

[steve5B]

   This doesn't make any sense, fuel pump seal is ok, injectors check out ok!,  cross over lines are not leaking, however I was

    thinking, would it be possible that the return line to the fuel tank be plugged up and not letting it return ( or is there such a

    thing?   I lost a injector several years back and the mechanic who replaced it said he dropped a washer or seal down it hole

    where the injector goes in.  Said it didn't matter, wondering now if that's the problem.



   Steve 5B........

[luvrbus]

could it be one of the plugs came out of the fuel galley that runs through the heads

[steve5B]

  Luvrbus,


  Where are these plugs located, and do you need to remove the heads?

   Steve 5B......

[Bob Gil]

I don't know much about the pumps on these engines but I did have a pump on an old chevy go out and it pumped the block full of fuel.

I don't think these engines have that kind of pump even thou my 3.9 cumins has i think.

Sorry I can be of more help.

[Lin]

This seems to be a really scary problem that, hopefully, has simple solution.  Please keep the info coming.

[luvrbus]

Steve I checked the book and they do not have a plug inside the head but the place where the lines attaches to the heads screw into the heads with a brass washer under them and the only other place I could see where it could leak was the body of the injector where the nut is it also a brass or rubber washer seal. I know these injectors will leak but that is a lot of fuel for leaking injector

[JackConrad]

    As was already mentioned. Remove the valve covers and look.  I think you will find a spot that is very clean (washed with diesel fuel). Doing this is about the simpliest, easiest and cheapest.  If you do not find any "clean spots", then you will have to dig deeper. 
    And of course, change the oil & filter before starting.  After the leak is found and corrected and the oil changed, I would spin the engine, holding the rack closed to circulate fresh oil before letting engine start.  Jack

[Busted Knuckle]

   This doesn't make any sense, fuel pump seal is OK, injectors check out OK!,  cross over lines are not leaking, however I was

    thinking, would it be possible that the return line to the fuel tank be plugged up and not letting it return ( or is there such a

    thing?   I lost a injector several years back and the mechanic who replaced it said he dropped a washer or seal down it hole

    where the injector goes in.  Said it didn't matter, wondering now if that's the problem.



   Steve 5B........

Steve,
How are you determining these to be OK? Visual inspection? If so you might want to go a step farther. When we had our problem we had 3 different Detroit mechanics pull the valve covers and inspect and tell us there was no problem (I'd already done the exact same thing before the 3 of them!)! Then a young shop helper from a shop we know (they hate buses, but like us) told me he watched his boss find a "mysterious" leak with a dye injector and a "black light"! Hmmm, OK sounds like an idea, now off to see Tommy and get some insight on this. Tommy was more than willing to loan me his dye injector, and even the "special light" he had, and even explained in detail how to use it, & what & where watch for!

OK now back at the shop I hooked up the injector and started injecting dye. We looked and looked and could not find any traces of dye. I called Tommy and told him my results. He suggested that I leave the injector hooked up @ 15lbs of pressure for a while and reinspect! OK we did this and found 3 cross over lines that had just a little trace of dye around the fittings, but not running down anywhere at all. OK called Tommy again in the AM & told him of this discovery. He confirmed what we had thought, that this WAS NOT WHERE OUR FUEL WAS COMING FROM since it wasn't even dripping!  He suggested turning up the pressure to 25 lbs and checking it after several hours. Again no luck. He told me he'd "try and get by there after he closed his shop." Well along about dark thirty he called and said he wasn't gonna be able to make it!
Well I was disappointed, but decided what the hey I'll look again myself now that it's after dark! Wow as soon as I turned on the light there was orange dye all over! I looked and it was running very lightly from the middle of the head to the bottom of it and running down the oil galleys.

OK I now knew I was infact finding fuel where it wasn't supposed to be! But where was it coming from? Well about that time my dad came up and we discussed it! Dad suggested that since it was a DDEC unit maybe we should try it with the key on or maybe running!
Well I got into position to watch and dad went to the drivers seat. Then he turned the ignition on, nothing. So I told him to go ahead and start it.
Whoa shut it down, shut it down! Fuel was pouring out off of 6 injectors and with the light the cracks looked like lightening bolts!
The next morning Tommy stopped by, and we told him what we'd found. He was very surprised and wondered if we were able to make it dark enough for him to see during the day. I told him to hang on a  minute and went next door to my buddy Mark's shop and borrowed several large welding blankets. Then We went in the bus and draped one from the front of the access hole down over the back of the bell housing and trans. Left one laying there to use as a cover. Went back to the back and used vise grips to hang a couple of them from the engine hood (Setra's open up and stick out over ya like a sun or rain cover!). With this done it was almost as dark as it'd been at night. Tommy went in the bus and pulled the one over the opening back and over his head. I had the ignition key on, and when Tommy said he was ready I started it from the rear position. Almost as soon as it started Tommy said shut it down. He came out of the bus with a half grin, and said "well I seen two things just now I ain't never seen before! One is I ain't never seen a dark room built out of blankets before, and two is I ain't never seen injectors leak like that before!" So as we discussed it he asked if I could leave it set up for dark a while. Sure. Then he went on to say if it were him he'd change all 8 injectors and all the crossover tubes & seals!
A little before lunch he showed back up with all his shop hands and mechanics, as well as 2 of the 3 (from different shops around town) that had told us we didn't have bad cross overs or injectors! When Tommy told me to I started it and he had the guys take turns watching what was happening! When Tommy told me to shut if off, everybody was surprised at what we'd just showed them.
We thanked them all for coming by and checking it out. And they thanked us for showing them what we'd found saying it could come in handy some day. Then we all went to lunch! While at lunch I tried to see if they were willing to "chip in and donate for new injectors, for the education they'd just received?" Unfortunately everybody politely declined, but someone did "mysteriously" paid for dad, Lamont's& my meals. So it wasn't a total loss!

So just because ya can't see it don't mean it ain't leaking!
And yes mine were DDEC and leaked in a way that 5 or 6 well known diesel mechanics from around here had never seen before. Just goes to show ya, with persistence and different methods it can be found and corrected!

FWIW   BK 

[NJT5047]

I don't know much about the pumps on these engines but I did have a pump on an old chevy go out and it pumped the block full of fuel.

I don't think these engines have that kind of pump even thou my 3.9 cumins has i think.

Sorry I can be of more help.

The pump on a DD has a weep holes so that if either seal fails, it won't impact the other side.  The problem is that the holes are tapped to accept 1/8" pipe plugs.  Often enough, guys plug the pump all up.  This is OK until a seal fails for whatever reason.
The goal is to leave the lowest hole open.   
Old fuel pumps with diaphrams would make a huge mess if the diaphram failed.  The DD pump is a small gear pump, so there ain't no diaphrams to fail.   DD fuel pumps rarely fail. 
BK has the best solution...dye.  That's the plan!
Best, JR 

[fe2_o3]

We had a series 50 shut down on the freeway the other day. The driver said the check engine light came on and she shut down. The oil showed way over full. The computer showed a low oil pressure fault. We changed oil, filter and injectors and she's back on the road. One of the mechanics said it's happening a lot more lately. Could be a fuel or injector problem. We're not sure which yet...Fuel for thought...Cable

[zimtok]

I was getting fuel in my oil on my 6-71 soon after we first got it.

I looked at all the normal things listed here and found nothing.

I then put an electric fuel pump on the system and that is when I noticed fuel oozing from around the injectors. This was not noticed while the engine was running because engine oil was mixing with it.
The fuel was coming from 3 of the injectors themselves. I pulled one of the worst ones out and found that the "O" ring seal between the Injector Nut and Injector Body was dried and brittle with cracks.

I located some seals at a local truck shop and took one Saturday morning to pull all 6 injectors one at a time and replace the seals.  I did a video of it and posted it on Youtube. I've had no problems since.

[mikelutestanski]

Hello:
       
   When I was having discussions about the new low sulfur fuel one of the concerns from the Cummins guys (RE mechanical L10 engine) was :
     You might have trouble with your fuel system because the new fuel does not have the same lubricity and some or all of certain o rings may deteriorate enough to leak by.
    So this may be a symptom of that phenomena occurring because of the composition or age of a particular elastomer. 
    FWIW
    happy bussin   Mike

[steve5B]

  Everyone !!!!!


   Thanks for all the info.......Not knowing much about buses in general this is a good place to start.  Here's what I decided to do.

    Had it towed to the local DD shop, told them to replace all injectors, cross over lines, fuel pump, replace anything and

   everything it might need!.  Hopefully it won't be to much because it was rebuilt 24,000 miles ago.   Also just a note, I did an oil

  analysis on my spectrometer  and it showed no ware , but high fuel dilution.   Will let everyone know when I get it back.  Maybe

it is the injector seals from the low sulfur fuel.


  Steve 5B....

[NJT5047]

  Everyone !!!!!


   Thanks for all the info.......Not knowing much about buses in general this is a good place to start.  Here's what I decided to do.

    Had it towed to the local DD shop, told them to replace all injectors, cross over lines, fuel pump, replace anything and

   everything it might need!.  Hopefully it won't be to much because it was rebuilt 24,000 miles ago.   Also just a note, I did an oil

 
  Steve 5B....

By golly that ought to fix it!   


JR

[Busted Knuckle]

  Everyone !!!!!


   Thanks for all the info.......Not knowing much about buses in general this is a good place to start.  Here's what I decided to do.

    Had it towed to the local DD shop, told them to replace all injectors, cross over lines, fuel pump, replace anything and

   everything it might need!.  Hopefully it won't be to much because it was rebuilt 24,000 miles ago.   Also just a note, I did an oil

  analysis on my spectrometer  and it showed no ware , but high fuel dilution.   Will let everyone know when I get it back.  Maybe

it is the injector seals from the low sulfur fuel.


  Steve 5B....

Steve,
Boy when you decide to get'r done......You get'r DONE! Wow, I probably would have told them check out what it needs and let me know! Then based on what they said it needed and cost would have told them ya go ahead, or well you do this and I'll do that! But it should be done right when ya get it back, providing they know what they are doing on 2 strokes! Just out of curiosity where are you located and what DD Dealer did ya take it too?    BK