Injection pump trouble 240D

Status
Not open for further replies.

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
I think I am having trouble with the #3 injection element in my 240D. I have been running a 50/50 (diesel/WMO) in the main tank for about a month now. I just set up my dual fuel system (which works great) about a week and a half ago. Over the last couple of weeks I have noticed the car (which used to run like a sewing machine) started to loose power. The first time it happened, I changed the fuel filter and it was back to normal. This time (a couple of days ago) I changed the fuel filter and nothing changed. Then, today, it started to run like it's running on three cylinders (slow, no power, smokes like a mosquito fogger, dances hip-hop at idle). I changed the fuel filter with no change. I swapped the fuel injectors with some I pulled from a boneyard - no change. So then I started to crack the fuel lines while the car was running. Cracking #1, 2, and 4 caused fuel to spray out in a mist and the engine wanted to die. When I cracked #3, however, fuel sort of oozed out and nothing really changed with the engine. Just for the sake of being thorough, I cracked the nut at both the injector and down at the pump. Same result.

Should this problem be isolated to one injection element since the rest of the engine runs fine? Can the injection element get the feed hole plugged over a period of a couple of weeks (doesn't seem likely)? Could the injection element just need cleaning? Could I replace this element with a boneyard pick? I know "the experts" say that each element is adjusted for certain fuel flow and timing, but how critical is it? You should see this car. It's not a beauty queen. I just need it to last a year and a half or less and survive my learning curve. Any other suggestions?
 

Josh Carmack

Full Access Member
Joined
Mar 7, 2013
Posts
368
Reaction score
2
Location
Ripley, TN
Fuel oozing out does not mean the delivery valve is not functioning, it could mean the injector is stuck open/popping way too early, the added smoke would add to that hypothesis as well. The fuel mist out of the other lines because both the delivery valve, and the injectors are functioning properly. I would suspect an injector way before I would a pump valve.
 

The Warden

MiB Impersonator
Supporting Member
Joined
Jan 12, 2005
Posts
7,356
Reaction score
34
Location
Fog Bless Pacifica (CA)
How well are you filtering the WMO?

The M-B injector pumps are pretty sturdy and don't normally give much trouble, but if the WMO's not being filtered well, IIRC it can wreak havoc with the pump internals (although I don't know all that much about running WMO, so I can't speak with authority).

As to replacing the individual element...without the equipment to calibrate it relative to the other elements, I would be very apprehensive. I don't know how to do the calibration, but if it's injecting significantly more fuel than the other elements, that'll make the engine run strange in its own right, and if it's significantly less, you'll have the same problem you're having now. I took a look through the factory shop manuals for the W123 chassis that I have on pdf file, and I'm not seeing any reference to doing any work on the individual elements, or any internal component on the injector pump...which tells me that even the M-B dealers expected their technicians to service the injector pump as a unit, and send it out to a shop for any internal work that would need to be done.

For that reason, I think I would find a boneyard injector pump and swap it in first. Given what you said about the car's condition, I'm guessing this isn't in the cards for financial reasons, but I'd be curious to see what a pump shop would have to say about the pump after disassembling it...
 

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
Josh, When I pulled the injectors, #3 had sort of a brown, spark-plug type of coloration to it. the rest looked like they belonged in a diesel. This is a completely different set. I think it would be difficult to get two bad injectors in the same cylinder by luck. I'm thinking it's not the injector.

Warden, I think I might pull the element that I suspect to be bad and see what I see. What's the worse that could happen? It won't work? Oh yeah, I'm already there. The boneyard parked one of these cars a few weeks ago. I think I'll go see if there is still an injection pump. They know me pretty well over there. I pull a lot of stuff. But I'm not sure I feel like changing the entire pump. It looks like a PITA to get the timing right.
 

Josh Carmack

Full Access Member
Joined
Mar 7, 2013
Posts
368
Reaction score
2
Location
Ripley, TN
In my opinion, I'd rather have a mis-calibrated delivery valve vs a dead one. One of these days, one of these days, thats what i keep saying about a lot of stuff, but I plan to use a grease gun to build a pop tester.
 

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
OK. I've decided on a plan... I'm going to see if the injection pump is still in that car in the boneyard (the car's been there for a month). I'll grab the pump if it's there. I know where there's a car that should have an injection element, but it's been open for a month with daily rains here. I'll grab that element anyway and put it in this car(I don't want a pump that's been open for that long). Worst case, it will be out of calibration - but the old element has been going out of calibration for two weeks and the car hasn't blown up yet. If the car runs fine, I'll roll with it for a couple of days and see what happens. If it runs better - but still like crap - I'll use the "repaired" pump to drive the car up on the ramps and replace the pump with the boneyard unit. I'd prefer not to have to jack up this car to get it on ramps. It has the suspension travel of a desert-formula puckup truck and it would be an all-day affair.
 

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
OK. I did a number of things today. The car is better, but it's DEFINITELY not good. I decided to try some things before I went messing with the pump, but I had to go to the boneyard before I did anything else because of time restraints. So... I have 2 boneyard injector pumps that I don't need. Oh well, I'll keep them for spares, but that's about $140.00 I didn't need to spend. I took the spring and holder out of my #3 injection element to see if anything looked really bad. Fuel started to backflow and ooze out of it. So I turned the engine over while I looked at all of the ports in the pump (the metal lines were off). They all seemed to squirt fuel. So I took some spare lines and bent them so I could bolt on injectors and squirt them into the air - and watch the flow. They all seemed to be flowing somewhat similarly. So I hooked the car back up and started it. It was smooth for about 1/2 of a second, but went back to what it was doing before. So I pulled the glow plugs for the hell of it. They were each crudded up with some white crap. One of them didn't even want to come out. So I replaced them with a set of boneyard pulls. The car started RIGHT up, but still ran rough. I drove it for the heck of it, fully expecting disapointment. To my surprise, it seemed to have its power back (or most of it). It still idles like a Harley Davidson, but it seems to drive almost like normal. I'm now suspecting some crudded-up prechambers. I think they are crudded enough to not give good fuel flow when idling, but the injuctors can push through it under load. I ordered some heat shields. When they get here, I think I will try cleaning out the prechambers and go from there.
 

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
It looks like I fixed it. Encouraged by the renewed power, I topped the tank off with Shell Diesel and drove it to work. About 10 miles down the road, I noticed that the car was idling normally again and it had quit smoking. When I got on the interstate, I was able to get back up to my top speed again. After a while, I switched to WMO and the car still ran fine. I think I will keep the diesel tank as pure D2 from now on so I get a good flush when I switch back from WMO. I might also start cutting my WMO with 15% rug. If I cut it before I centrifuge it, it will probably help pull out more gunk.
 

The Warden

MiB Impersonator
Supporting Member
Joined
Jan 12, 2005
Posts
7,356
Reaction score
34
Location
Fog Bless Pacifica (CA)
Congrats on it being something relatively simple ;Sweet

FWIW, if gummed-up precombustion chambers are really the only problem, you can remove them and clean them (or possibly replace) if you really want...send me a PM with your E-mail address and I can E-mail you the pdf file (it's too big to post here, unfortunately)...
 

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
Thanks, Warden! I sent a PM. I'd welcome any info I can get on this thing. So far, this car is serving its purpose. It's keeping the miles off of my other car while I learn about burning oil in something that's forgiving and bulletproof and cheap to fix. Once I get good at it, this car will become a 1 ton 4x4 king cab pickup with a Cummins and a manual transmission. I just have to get through 600 gallons of oil first...
 

Turbo OM617

Registered User
Joined
Nov 19, 2006
Posts
27
Reaction score
1
I think I am having trouble with the #3 injection element in my 240D. I have been running a 50/50 (diesel/WMO) in the main tank for about a month now.
...
Any other suggestions?

Stop running trash through your injection system. WMO, especially diesel oil, is fine for plain bearings in an engine but the soot is highly abrasive to injection pump elements and injectors.

So I pulled the glow plugs for the hell of it. They were each crudded up with some white crap.
That is ash from engine oil contaminating your fuel.

FYI, engine oil is designed to not burn! Thats why shop heaters designed to burn waste oil cause heavy dust in the shop and require yearly cleaning.
 

paramax55

Full Access Member
Joined
Aug 16, 2014
Posts
93
Reaction score
1
Location
Florida
Um... Turbo OM617... why are you saying stuff like this on such an old thread? How much WMO have you burned so far? The problem is fixed. I've burned over 400 gallons so far and I hate when I have to burn diesel. In fact, now I'm running W85 instead of a 50/50 mix. The engine runs a lot smoother and the whole fuel system is a lot cleaner - I know that because all of the crap from the diesel ended up in the filters after it came loose. Overheating and coking was fixed by advancing the timing 2*.

Why would you come and tout all of these "facts" about something of which you have no experience?
 

Turbo OM617

Registered User
Joined
Nov 19, 2006
Posts
27
Reaction score
1
Um... Turbo OM617... why are you saying stuff like this on such an old thread?
This isn't a free country and this thread on a public forum isn't open? Well, crap, sorry, my mistake!
Feel free to not read any more posts to this thread. Anyone else following up on this thread in the future will be able to learn from a professional about how destructive and foolish your actions are without your interruption derailing the thread.

How much WMO have you burned so far?
I'm a professional, I know better than to run trash through my precision machine.
I work hard to keep my machine running in peak condition for many years to come. 2 micron fuel filter, high-quality synthetic engine oil, 2 micron bypass oil filter, exemplary maintenance schedule, clean combustion tuning.
No matter how much you filter the oil, run it through a centrifuge or cut it with engine damaging gasoline, you will never get the soot concentration to a level that won't accelerate wear of the injection system.
And as stated before, engine oil is designed to not burn. When it does it burns extremely dirty, drastically increasing emissions, and forms high levels of ash that coke up your combustion chambers and contaminate the engine oil, accelerating bearing wear.

the whole fuel system is a lot cleaner
That is false information.

Why would you come and tout all of these "facts" about something of which you have no experience?
I'm sorry, you have no experience. Using quotation marks around the word "facts" is neither witty or changes the proven fact you don't know what you're talking about.
 
Last edited:
Status
Not open for further replies.

Forum statistics

Threads
91,217
Posts
1,128,473
Members
24,044
Latest member
Mnlx
Top