Injection pump maintenance
 

Any routine maintenance that should be done on the injection pump? I assume oil change to begin with, though I don't know the procedure nor the correct oil the replace it with...

Do you have access to the W123 FSM? There are several mentions of your injector pump (the one for the OM615) in section 7.

You might be able to access it via www.startekinfo.com

Click on "MB Workshop Resources" then "Service Manual Library CD DVD"

There have been loads of problems with this site though - for a full appreciation see

http://www.peachparts.com/shopforum/general-information/310495-mercedes-startek-have-done-right-thing-help-you-do-right-thing.html

as to my knowledge,it is same oil engine uses so proper engine oil change
will do the trick. Besides that one, people do injection purge (diesel p.)
which cleans injectors and pump itself, filter change is a must, however...

some tweaks are also possible but not recommended for novice (like me :) )


cheers


.

Oh I forgot to mention there's loads of chat about your IP and its associated system in this thread

http://www.peachparts.com/shopforum/diesel-discussion/307688-om-616-injection-pump-timing.html

1969 220D - 4spd std
1973 220D - 4spd std
His earlier Fuel Injection Pumps are most likely not lubricated by Oil From the Engine.


The Oil inside of these pumps is much cleaner than the Engine Oil lubed ones because there is no contamination from the Engine.
However, there is a little bit of Fuel that leaks by the Elements and mixes with the Oil in the Fuel Injection Pump over time; more so if the Elements are worn.
Also the Oil can evaporate over time and use.

Some of the non-engine lubed Pumps have a drain plug to draining out the old Oil but most do not.
In one of the thread someone described using one of those big squeeze ball Turkey Basting Syringes with a skinny tube attached to it so you can go down through the Oil Fill Plug in the Fuel Injection Pump and suck out the old Oil.

When you Fill the Oil some of the IPs have either a bent Tube (sort of an overflow Tube) that the Oil will run out of when it is over filled or it has a Plug (not unlike a differential or standard Transmission Fill/Level Plug) and you fill it until Oil comes out of the plug hole.

For mor info:

DIY Repair Links
DIY Links by Parts Category - PeachParts Mercedes ShopForum

PeachPartsWiki: Do It Yourself Articles - Mercedes Vehicles

I'll assume that we have the same injection pump or at least very similar...

As mentioned above, you don't have an IP that's lubricated from the engine oiling system. It has to be drained and replaced on a somewhat regular basis.

I had difficulties draining the old oil and mixed fuel out of my W115. I removed the red "Oel" cap and attached an oddball arrangement of small diameter tubing and electrical tape to my hand operated fluid pump. Eventually I was able to work it to the bottom of the IP and pumped out several quarts of old oil and diesel fuel. I wouldn't be surprised if you also find some diesel in the mix.

There is an overflow tube on the engine side of the IP that prevents it from getting too full of fuel that, hopefully, will never see any use.

Once you have the old crud out (either my method or working your way to the drain plug), you'll need to top it off.

There's an overfill plug on driver's side of the IP near the primer pump.

http://farm8.staticflickr.com/7024/6...52d1c11b_b.jpg


It can be tough to get too, but it's not impossible. A boxed wrench and a moderate amount of contorting should do the trick.

Loosen this and add about 1/2 quart (but probably less) of your favorite engine oil. Stop adding when it begins overflowing and retighten.

Rinse and repeat every other oil change or more often if you wish.

Wow. That little thing doesn't even look like it could hold that much fluid:eek:

Great posts, thank you for sharing your experience on a 115 bipolardave.

No problem.

I could be overstating, but it was a bit more than I thought healthy. Again, you might not have anything but motor oil. YMMV.

The picture from above was just after I had my IP rebuilt. I checked the oil level a few days ago and no fuel leaked out so I think my fuel seepage problem has been corrected.

You don't have to drain out the old oil at every change. Open the plug on the side, add about 6.5 fluid ounces (200 ml) at the top until clean oil comes out. Diesel fuel will be lighter than oil, so that will come out first.

More data
 

Due to the Diesel Dilution issue where I worked we used to use 40Wt Oil.

As for how long between Oil changes you need to establish that for you particular Pump.
Pumps that are worn will have more Diesel Fuel in the Oil in a shorter time than one that is not.

You simply have to check it every month or 2 and see what happens. After you know you can come up with some sort of schedule.

Thanks for the info gents, just suctioned off a good 50ml of diesel off the top (out of the "Oel" cap filler hole), removed the plug to the right of lift pump, and topped off with Delo 400 until oil ran clean out of plug. Made a huge mess in the process... I'm guessing 50ml of diesel means somewhat tired injection pump. I know that that "Oel" cap has not been removed for near two years, so hopefully that 50ml stretched out over two years isn't a sign of impending injection pump rebuild?

Speaking from my limited experience, probably not. That doesn't seem like a huge amount to me. If a little diesel in your IP is the only issue that you're having, consider yourself blessed :)

Rebuilding the IP isn't something that folks ordinarily do. The only reason that I rebuilt mine was because of a small vacuum leak in the governor. While I had it out for that, I thought it prudent to take it to a Bosch shop and have them give it a once over if, for no other reason, preventative maintenance. ~$800.

My car now starts easier, smokes less, and is much smoother at idle. I haven't yet been able to test for better fuel economy, but hope to when we get nicer weather.

Proper oil for the OM615 IP?
 

What is the general consensus of the proper oil for the OM615 injector pump?
I've searched around and haven't specifically found any answers since a lot of folks are using a lot of different oils on cars across the spectrum of condition from new IPs to worn out IPs

I've seen folks using multigrade dinosaur, multigrade synthetic, monograde dino and monograde synthetic.

Add to that, does it need to be specifically diesel rated oil or can standard oil for a gasser be used?

Yesterday I sucked out a few ounces of what seemed like straight diesel and added gasser 30wt up to the overflow bolt hole till it dripped out.

So, can I keep using gasser oil? Should I replace it with diesel rated oil? Monograde or multigrade?

Thanks all,
Phil Forrest

Besides the oil change, the rack damper and fuel return spring are wear items.

You need diesel-rated motor oil in the engine because it has to deal with the soot produced in the combustion process. In the injection pump there is no soot, only the camshaft of the IP needs to be lubricated. So you can use more or less any engine oil. Because the oil needs to be changed every time you change the engine oil, it is most practical to use the same oil as you put into the engine.

A little amount of diesel seeps past the pressure cylinders of the IP. This is to lubricate. That diesel collects in the oil sump of the IP. That is the main reason why you should change the oil in the IP. So if open up the bolt, diesel will come out, certainly if you haven't changed the oil in a while.

Excellent!
30wt dinosaur oil is really cheap, even from a top brand so that's what I'll use. I have a few quarts anyway so that'll last me a long time.

Phil Forrest

Last night the 220D was running well. I fixed a bunch of electrical issues and got everything but the blower working. It was all corroded contacts.
This morning I adjusted my valves on a dead cold engine and afterwards the engine idles way too high. Its probably double what it was doing last night.

I have the intake off and the engine will *almost* die if I plug the vacuum line to the IP. It will shut off normally if I use the starter to shut down the IP.

So now I'm wondering if one of the linkage rods got out of adjustment when I removed the valve cover? The high idle cable is slack so that's not the issue.

Any help is appreciated.

Thanks all!

Phil Forrest

Sounds like you've knocked off the vacuum line that runs from the venturi to the back of the IP governor's "bladder"

(PS with your photographic skills you really ought to some MB pictures)

That's what I thought at first but it is there and it is intact. I can plug the llittle vacuum line port at the plenum and just about kill the car. Is there another vacuum line back there?
I pulled off the IP oil filler cap and stuck my thumb over the hole. No engine rpm change or different colored smoke.
This thing is confounding me and I want to make sure I don't wind up with a runaway on the freeway or worse, in town on a crowded street.

I'll be posting more Benz photos, surely. I just need to get this maintenance done first.

Thanks,
Phil Forrest

The accelerator pedal controls the butterfly valve in the intake manifold. From there one rod runs over the valve cover. It connects via a lever to the rod to the auxiliary mechanical governor at the back of the governor housing. If you knock those rods out of whack it will not idle high, but rather low. You could have done something to the control rods from the accelerator pedal to the butterfly valve, but if you remove the valve cover, it is unlikely. The rod runs across along the firewall to the passenger side of the car.

It could also be that the idle was adjusted on the wrong valve clearance, now that the valve clearance is ok again, the idle can be higher. A double idle is however unlikely.

Maybe you removed the spring from the butterfly valve assembly. The spring is there to return the butterfly valve to the idle position.

You could have damaged the vacuum line to the IP, an air leak will cause a high idle.

I can't find any damage in the vacuum line to the IP.
Butterfly valve still closes properly. The valve behind it just flaps freely as I believe it is supposed to, moved only by air volume.

Linkage rods look ok. All are connected and lubed up at the ball joints.

Adjusting the idle screw on the throttle body can't lower the rpm any more. Only shortening the mechanical governor linkage or restricting the vacuum to the IP will lower rpm.

Thanks for the help, keep it coming!
Phil Forrest

There is only one big vacuum line from the intake manifold to the governor of the IP. Putting your thumb over the oil filling opening doesn't affect the running of the engine, because there is still ambient pressure on that side of the diaphragm.

First adjust the linkage to specs, especially the mechanical auxiliary governor. Do you have access to the FSM?

Is the spring of the butterfly still there?

Have you read these threads on how the pneumatic governor works?
http://www.peachparts.com/shopforum/diesel-discussion/327679-ip-running-full-open-74-240d.html
and this one, with a test to test the air tightness of the governor house:
http://www.peachparts.com/shopforum/diesel-discussion/313733-74-240d-grey-smoke-questions.html

Yes but reading about IP diaphragm leaks, putting one's thumb over the filler hole is one way to diagnose a leaking diaphragm. Unless I'm reading a thread wrong.

Phil Forrest

Not really. Better method is the one described in the threads (which is a copy of the test in the FSM).

I just put the MightyVac against the vacuum connection on the IP and it won't hold anything. Diaphragm leak, yes?
I'm pretty sure I got a good seal against the fitting.
(This is the part where I use profanity off-forum.)

But I tried to get vacuum against my thumb which was covering the oil filler hole and felt nothing there either. I have a known good MightyVac as I just used it last nitght and tested it right before I stuck it on the IP housing. Could the fitting be leaking perhaps? Is there another port of air entry into the IP?

Thanks all,
Phil Forrest

Did troubleshooting on the IP and idle speed all I could today.
After not getting the governor to hold a vacuum, I'm of the opinion that the diaphragm might be leaking but I couldn't get eh vacuum to pull on my thumb blocking off the oil filler cap so perhaps the leak is at one of the shaft seals?

This thing is a bit confounding but I think I've dealt with worse before.

Thanks for the help and advice. I can always use more.

Phil Forrest

If the governor house doesn't hold a vacuum, it can be because of a torn diaphragm or a leaky axle bearings of the poppet cam or both. The axle bearings almost always leak when they never have been replaced.

You can take off the governor and inspect the diaphragm.

Read also the FSM
07.1 Diesel Injection System - OM616

section 07-125, 07-130, 07-215

When I take the governor off, will there be any small pieces trying to fly away? I have a deep aluminum tray (for cooking) that I'll stick underneath to catch anything that may fall but it looks like only the spring is a lose part on that side of the diaphragm.

Also, will the diaphragm possibly be wanting to come away with the governor housing when I take it off or is is positively attached to the IP side?

Thankfully this area on my car is very clean so I'll be able to see better what I'm doing and just maybe the screws won't be all seized up.

As for the leak, I know the poppet cam axle feels a little loose so it's my first suspect. I'll start the motor and dribble a little oil on the shafts of the cam and start/stop switch to see if I can locate the leak.

I stress out these little (or big)maintenance problems at first but the Mercedes have proven to be so simple and reliable that fixing them is not hard at all.

Thanks to the forum members for all your help!

Phil Forrest

Just dribbled some heavy gear oil on the poppet cam shaft and there was an obvious drop in rpm with the motor running. Couldn't find any other leaks but it's now time to tear apart the governor (remove it from the IP) and see if the diaphragm is leaky.

EDIT: After disassembling the governor I found that the inboard side (engine side) of the shaft which rides in a bearing, had gotten some grit in via the very hardened rubber seal. The seals had basically turned into something like bakelite and although they are still intact, I know I could break them easily. The grit wandered around and narrowed the shaft by a few thousandths of an inch.

http://gallery.leica-users.org/d/363...oppetShaft.jpg

There's not really any option of repairing the shaft itself. Its probably garbage which I'll use in the future as a punch or something of the like. Now the question is, where do I get a replacement shaft? Or should I just take it to a machinist and have a piece of tool steel stock turned with the e-clip notches, the poppet cam locking screw and flats for the linkage arm?

I gently pulled out the diaphragm on the IP side just enough to shine a small LED light from the back side and there is at least one pinhole in the diaphragm.

Since it's a pinhole, is there any hope of repair? Silicone or something like that? I've read in another thread that someone may have tried repairing the diaphragm with some good silicone caulk but I'm not sure of the longevity of the repair. That dang cotter pin which holds it into the IP looks like a pain in the @$$ enough that I want to do this once and only once, so I'd rather find the new part and do it right the first time

So now that I know the diaphragm needs replacement along with the poppet shaft and seals, where the heck do I find these parts?

Phil Forrest

The diaphragm is connected to the rack and the ring will probably be stuck to the IP, so there is no fear the diaphragm will fall out.

The governor spring will fall out and the pre-load rings for the spring. There are probably a couple of them in there.

Instead of hijacking the thread with multiple posts, I just edited my previous post to include the new information with a photo of half the problem.

The repair looks simple. Getting that cotter pin in to hold the diaphragm looks like the worst part but other than that, it's not a hard fix.

I just need to find a diaphragm, poppet shaft, rigid poppet "chamber" seal and some O-rings which will fit properly and not impede the turning of the poppet shaft.

Thanks for the guidance!

Phil Forrest

Getting the pin out to remove the diaphragm is not that complicated. Getting in back in is more tricky. If you drop it, it can be fished out by means of a magnet on an antenna. You must also set the compensation path (described in the FSM), you need a micrometer dial for that.

http://i185.photobucket.com/albums/x...d/DSC_0702.jpg

And watch out for the parts in the diaphragm:

http://i185.photobucket.com/albums/x.../membraan2.jpg

The diaphragm is double layer, so did you look straight through the diaphragm? I would just replace it, but perhaps a repair will work, but I'm knowledgeable about it.

The diaphragm is still obtainable I think. The poppet cam and axle are more complicated. The back cap including axle and cam used to be a (expensive) repair part sold by MB, but it is NLA nowadays I believe. Bosch also sold the parts (bearings, O rings and rings, axle) seperately, but they are also hard to find nowadays and I think the bearings are only sold in sets of ten. Sometimes you can find a diesel service which sells the back caps for cheap. Otherwise junkyards. Perhaps you can use generic bearings.

I didn't take the diaphragm all the way out yet but did shine light all the way through it so there's definitely a hole big enough on the IP side to allow a decent cone of light in to illuminate the pinhole on the governor side.

The bearings look fine. That shaft is the big problem unless I can find the part from a junkyard and it's also not toast. I'm thinking that having a piece of stainless machined down and drilled properly might be the cheapest route to go.

I also have to either find the proper gasket or make one out of rigid gasket material for the governor cap to poppet housing. Maybe a .5mm sheet of hard rubber can be cut to the proper dimensions to make the gasket.

I have a Benz dealer searching for the part but everyone is closed now so I have to wait till Tuesday (Monday is Labor Day holiday) to even hear anything back from anyone.

Till then I'm going to have to put everything back in so i can move my car so I don't incur a ton of parking tickets due to street sweeping. <--*--THIS* is the reason I have been asking for the last 6 months about a place to work on my car in a place to rent or maybe even a nearby driveway. Hopefully, I can get an answer by Tuesday and a part by the end of the week or else I'm going to have to figure out some long term storage solution.

Phil Forrest

Is there a gasket for around the diaphragm to seal it?
When I took the governor off, there was no seal on the back side of the diaphragm. Is there one on the front which needs to be replaced?
My genuine Mercedes IP diaphragm just arrived today and I want to get the car back up to snuff tomorrow if possible.

Phil Forrest

No, the outer ring of the diaphragm is the seal.

When getting the diaphragm back into the IP, I have to set the compensation path? Won't it work by simply setting up the diaphragm using the exact same number of shims as in the old diaphragm?
I still haven't gotten a hold of a w115 / OM615 FSM and paying some of the ebay prices for a stained, yellowed, falling apart book seems ridiculous.

Phil Forrest

Perhaps, but you are on your own if you do that. How bad it is just to put in the old shims I do not know.

For replacing the diaphragm and setting the compensation path, you can use the W123 FSM as well:

07.1 Diesel Injection System - OM616
Just use the chapters for the IP with pneumatic governor.

Thanks for the link. I had been looking around in there for the pneumatic governed IP adjustments but couldn't find them.
Looks like I need 1.1mm of depth/travel. Doesn't matter since I don't have any compensating spacers anyway.
I'll keep my fingers crossed and hope it works.

Phil Forrest