1963 om621 Diesel Timing

[dog63benz]

Checking the timing on new project. I have the notch in the washer lined up with the bump on cam mount. Pointer is at 6 Deg BTDC. Don't have a manual just looking on line and this just doesn't look right. Car isn't running has fuel issue so just checking everything before I procede with IP removal.
Any thoughts?

[vox_incognita]

Had the same "issue". No matter how hard I tried to "prefectly" align the pointer on the cam tower with the roughly cut notch on the cam washer I'd always get a reading BTDC(true, I was not sure whether it was the original washer.Car started and ran fine) . Anyway many people would say the reading on theirs(w115;123's) was "spot-on"...others would say it was a rough test and the dial indicator procedure was the only valid one(I agree).

I'd advise you to obtain the FSM and follow the correct dial indicator method for checking chain elongation(it is different for om621)...and reinstall the IP according to the drip method @ 26 degrees BTDC (the procedure is the same on om615;616;617).

BTW what exactly is the fuel issue ?

[dog63benz]

Fuel issue, drained all lines, tank of old fuel. New filter, new fuel then pumped up with hand pump. I can get fuel to the IP but not past it. I always thought you could bleed to the injectors. Cranking over doesn't pump fuel either. I know pumps don't usually wear out, could something be clogged or stuck in the IP? So I'm looking at pulling IP and having it checked out. Ordered a FSM today. Thanks

[vox_incognita]

Bleeding past the delivery valves is done by cranking the engine*. With hand priming one saturates the fuel lines,filter and IP fuel chamber(open the bleeder nipples on top of the the fuel canister and IP to evacuate air).
Having some transparent fuel lines helps a lot. I'd change the fuel hoses with new ones ,new clamps and install a plastic transparent pre-filter in the place of the aluminum factory one. Would upgrade to the newer style hand primer pump and check the condition of the lift pump valves and by-pass valve(I believe on 190Dc the by-pass valveit is mounted on the fuel filter body and not on the IP itself).It makes a big difference!

For the IP timing- there are hundreds of threads on the site:
https://www.google.com/search?q=ip+drip+method+site:peachparts.com&lr=&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjy3viksYDdAhUO3Z8KHTYMCtYQ_AUICygC&biw=1280&bih=617

Check what people with om615;616;617 do. Om621 differs a bit:
- Tuning is done with Crank Shaft set @ 26degrees BTDC (compr.stroke of course)

-Start/stop lever must be in "driving"position(pull the gorilla knob as it would be while driving the car).Better yet,disconnect the gorilla know cable and wire the start/stop lever in rearmost position -this is "max delivery"(starting postion..the lever needs to obercome the spring tension of the full load stop screw on the back of the IP).


-This is not mentioned often(and applies to the above engine models too...),but we need to make sure the injection timer..(and the intermediate shaft respectively) has not stopped somehow in advanced position (in older manuals one would see a combination of a big offset wrench on the injection timer nut and a spring attached to the camshaft sprocket-check the attachments below...need to remove the vacuum pump...but let's presume it's an overkill for the present...)

-the copper washer resides between the delivery valve body and the holder.The setup incorporates an o-ring too(between delivery valve holder and pump body).You need to renew both.



Set CS somewhere early...say 60-50 degrees BTDC.Mark the position of the IP body in relation to the engine block(I'd hate to bend them injector lines after the procedure.Undue stress on delivery valve holders too!.)...Remove the aluminum clamps between del.valve holders #1 and #2(10mm screws...these should be tightened very lightly..again to avoid too much stress on the holders...somewhere 7-8Nm...) Clean carefully the area around IP delivery valve holder #1. Use 19mm socket to unscrew the delivery valve holder on element #1. Remove the spring and the delivery valve plunger(#4"pressure valve" on pic).Leave the delivery valve body in(#6"pressure valve carrier"on pic) .Reinstall the delivery valve holder with the old copper washer.Tighten ,say,25-30Nm. Install a drip tube(cut an old injector line...or use some of the existing ones).Prime the hand pump a bit.Rotate slowly the crankshaft and when near 26degrees observe carefully the flow...the correct IP postion in relation to the engine block(CS set @ 26 degrees BTDC compression stroke) is where the drip flow is reduced to 1 drop/second(om621 is kinda different..it said AFAKremember "until fuel has just stopped flowing.One drop may follow in 10-15 sec.").Note what the scale on the CS ballancer says at this precise moment(now you will know where/if to rotate the IP after you've loosened the nuts..).If you need adjustment set the CS at 26degrees BTDC @ compr.stroke again...remove inj.lines,loosen the IP securing nuts...with CS position still on 26degrees BTDC @ compr.stroke slowly rotate IP body in order to achieve the desired flow.Tighten and repeat to verify .
After the tuning reinstall the delivery valve plunger,spring and holder with new copper washer and o-ring(lubricated). Tightening sequence for delivery valve holder in three steps : 30Nm-loosen-30Nm-loosen-35Nm final.
25Nm for the injector lines.

There is a coarse method(like the camshaft tower/washer scenario)-mark the position of the IP body in relation to engine block. Remove IP.Align the mark on the IP body and the splined gear(the missing notch).Reinstall IP with CS @ 26degrees BTDC compression stroke.Done. But I would not count on that.

After the IP timing check/tuning...hand prime the fuel system...bleed air from fuel filter and IP fuel chamber...crack open the fuel lines at the injector bodies and while holding IP lever pulled back(as if you are pulling the gorilla knob) crank the engine using a DIY remote starter switch.Tighten the fuel lines to prescribed torque and try to start the engine the usual manner.

*If there is no fuel delivered past the delivery valves with bled system and the start/stop lever in the right position etc...the rack might have been stuck in "stop" postition(the pneumatic governor spring cannot overcome whatever hinders the free travel of the rack).

https://www.pelicanparts.com/cgi-bin/ksearch/pel_search_2016.cgi?command=DWsearch&description=A0179974148

https://www.pelicanparts.com/cgi-bin/ksearch/pel_search_2016.cgi?command=DWsearch&make=MBZ&description=A0019973440

https://www.pelicanparts.com/catalog/SuperCat/3134/MBZ_3134_FULFUL_pg2.htm#item4

[dog63benz]

Thanks Vox ordered a manual and some parts. Got plenty to putz while I wait

[dog63benz]

Vox you were spot on! I pulled the pressure valves and they were stuck solid. I put in new seal/washer and still no fuel past them. So the rack and plungers under the pressure valve must be gummed up. I'm going to pull the IP. I have set the timing at 26deg BTDC and marked the IP body to block placement. Is there anything else I need to do before I pull it off?
Once off can I just pull the side plate and soak the heck out of the workings inside? Can I safely pull the butt end off and move the rack to check the diaphragm?

[vox_incognita]

Remove and drain the oil carefully in a container and observe whether it's too diluted with fuel.The IP is lubricated by engine oil in its own sump,appr. 250 ml(until it overflows from the check screw). Do not forget to fill after pump re-install.
You can remove the side plate and check the rack for free travel. There is a rubber gasket there,very solid one(#50 on the diagram)..I don't think you'll have leaks after that.If you do,they're sold as repl.parts. Same goes for the gasket of the bottom plate.
Do not disturb the screw connections on the clamps for the plunger sleeves on the IP rack !

To check the condition of the IP diaphragm, hold the start/stop lever in full stop position...put your thumb on the vacuum connection on top of the diaphragm housing(you know,the connection for the tube that goes to the intake duct.Be careful not to crack the line when you move the pump).Release the start/stop lever while keeping the connection plugged..you should feel the vacuum created.Control rod can move but slowly.Once you lift you thumb the IP rack should plunge forward to full load. If there is a small leak in the diaphragm the car will idle higher...if the rupture is greater it will run away after starting the engine.

There is a cylindrical plug in the front end of the pump body-it's the IP rack end plug , you can check the freedom of movement or the rack from there too,but removing the side cover will give you an idea how things actually look.

Have a look at this diagram,these are the o-rings and gaskets on this pump.
Diagram of a PES4M:
http://www.reparationinjecteur.co.uk/Files/113801/Img/24/1417010001.jpg

Google Bosch 1417010001 for a gasket set.

Make sure no dirt enters the IP fuel chamber! Isolate the entrance points when cleaning. Same goes for the delivery valve screw connections.In case of "resinification" the manual suggests "fill clean gasoline into fuel feed connections and let it act for a short period on elements".

MBUSA have granted free access to FSM for some models so I'm not violating any rules by placing some links here(whatever concerns vacuum controlled IP applies to om621 IP too):
https://www.startekinfo.com/StarTek/doclist.jsp
https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/07-200.pdf
https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/engine_77_4d.htm


You can remove the bottom cover to have a look at the IP shaft.
I would check the condition of the by-pass(overflow)valve too (dozens of threads on this forum...yours is the one that can be dissassembled..open and check for broken spring or stuck ball)
https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/07-145.pdf

While you're there you can check the condition of the IP lift pump valves (#502)and change the o-rings (#500). There is a small o-ring for the lift pump plunger rod (#507) that I would change too. This prevents fuel dilution of the IP lube oil..and introduction of oil in the fuel.
Repkit for the two valves Bosch 2447010044 = MB A0015861207 (#500 +#502 , two pcs.)
O-ring for plunger rod (#507) p/n Bosch 2 440 210 002 = A 010 997 86 48 *

On pump reinstall put a light coat of grease on the paper gasket between the block and pump body to facilitate the fine adjustment...gasket is cheap and used on many models.

To remove the diaphragm,
https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/615/07-215.pdf

Remove the governor housing. Inside you'll find the control spring with a set of washers.
http://www.peachparts.com/shopforum/attachments/vintage-mercedes-forum/49262d1194451807-om615-glowplug-conversion-001947409.jpg

http://www.peachparts.com/shopforum/attachments/vintage-mercedes-forum/49263d1194451844-om615-glowplug-conversion-001947406.jpg

Remove the back plate(there is a rubber gasket #85..space is not pressurized,bottom is basically part of the IP oil sump). Locate the circlip for the diaphragm on the control rack end.Remove the diaphragm making sure you do not lose any of the internals that go into the diaphragm sleeve(compensating bolt,set of washers and spring).
If you need to replace the diaphragm,you need to first measure the travel of the compensating bolt on the old diaphragm,using a 6mm bolt as a "imitation" of the IP rack pin...note the travel...transfer the compensating bolt +spring_washers to the new diaphragm...measure agan...and if not in specs(+/- 0.06mm),add/remove/sub some washers to match the old travel.

Hm,I wonder..could the diaphragm be so gummed up that the IP rack just refuses to travel?Anyway,after you've disconnected the diaphragm from the IP rack end you'll see where the obstruction is ...or a combination of factors..


*to remove the lift pump roller follower,knock out the vertical pin.Remove the follower assembly and the rod. The o-ring resides in a groove inside.Remove,oil the new o-ring and reinstall.
If the lift pump plunger spring is shot/weak/rusty etc, you need MB 0009934801 = Bosch 2 444 617 010 (#4 on the diagram). Note spring #8 is not used on later models..it is not necessary.

http://www.peachparts.com/shopforum/diesel-discussion/294499-refreshing-fuel-pump-om617-european-spec-%96-non-turbo.html
...pumps differ but the basics are the same.

[dog63benz]

I've done all that I can with the suggestions from Vox and others.
As Vox thought the rack was stuck, the delivery valves stuck and the pistons not rotating or moving up and down. After freeing the delivery valves and cleaning the pistons they now rotate when the rack is in the start position and go up and down as required when the IP cam is rotated.
With no fuel lines on from the IP to injectors I've bleed the system with the hand pump and rotated engine while hand pumping (rack in start position) and still can get no fuel out of the IP.
To me everything looks like it should pump fuel. I have to be missing something?

[vox_incognita]

Did you check the condition of the fuel in the IP chamber(any rust...gunk..sediments ..."resinification" there)?
Hm..we don't know the history of the pump/vehicle (somebody might have tampered with it in the past.). But if you have not disturbed the positions of the clamped connections for the plunger sleeves on the rack ...and everything is the way it is supposed to be I would do this:

-make sure the IP fuel chamber is getting fuel when I'm priming the hand pump. Having transparent fuel lines helps a lot! If in doubt,disconnect the fuel line on filter canister bottom or at IP entry and watch the flow. If flow is insufficient/absent with good filter the canister hollow stem might be plugged-clean and blow with compressed air..making sure no crap remains in the stem.Or...you can remove the by-pass valve and observe the flow there...

-if we're getting sufficient flow from the fuel filter canister outlet(or the by-pass valve connection)...we now need to make sure the fuel actually enters the plunger-barrel assemblies. I would not rule out the possibility of plugged barrel entry ports. You can remove the IP fuel chamber entry fitting and using a lit endoscope(or strong light..if the IP is on the table) observe the plunger rotation through the first element entry port as you move the rack .Tricky job though...or again,removal of delivery valve and spring will let you know whether fuel gets to this barrel...takes another set of copper washers...

-if the IP fuel chamber is clean and we're getting fuel in the barrels..then ,with IP fuel chamber free of air(do the bleed procedure described in the previous posts) we should see fuel past the delivery valves when we crank the engine. I would not count on hand rotating the crank by the 27mm. ballancer bolt... I'd connect the high pressure lines at the delivery valves and tighten but let them loose at the injectors...bleed the system...making sure I'm getting resistance while hand priming...then crank the engine with the starter or remote switch(with IP rack in the start position..yup,double check it's there..it might have been stuck again precisely at this moment )...and watch for fuel spilling at the loose connection up there at the injectors(do this test first,before anything else described above).

BTW was there excessive fuel dilution of the oil in IP lubr.sump?

[dog63benz]

Yes there was fuel dilution in the oil when I first drained it.
With the amount of junk around the pistons I'll bet the port holes that your describing are plugged. I need to order more seals and I'll try and look at the ports.
Thanks Vox

[dog63benz]

So looking in the fuel chamber entry port I can see the #1 and #3 plunger barrel. There looks to be a slot at the bottom of the barrels is that where the spill port is? Can I safely remove the plunger barrels to get a better look at the plungers? I read some where not mess with the barrels and to be carful not to let them ride up out of a slot or grove as they are hard to get back correctly.
I still think that fuel is getting to the plungers and when the new seals arrive I'll bleed the system and crank with the battery for pressure not the hand pump. Thanks again, seals are a few days out. I ordered two sets, should have done that the first time, there cheap!

[vox_incognita]

Doable,but as a last resort...remove del.valve assy ...push down on the barrel(it might have attempted to come up as you tried to remove the delivery valve body)...and measure the distance from IP top surface to barrel top...triple measure ! Using a magnetic pick-up tool carefully extract the barrel.It can be installed in only one position(there is a slot there..check the attached photos).It MUST fit precisely back to its original position (same depth..should not protrude higher than before).Triple check again before reinstalling the del.valve assy. !
Sliding the barrel back takes some careful wiggling on the plunger...Done it once ,frankly I'd hate to do it again.
The entry/spill port is visible on the first pic @ 9o'clock,top portion.


Once again,I'd try the other options first.

[dog63benz]

It runs! I ended up pulling the barrels out as there was resinification in the ports. Very tedious job. Still need to time it but it run ok and had good oil pressure. It had sat since 1982.
Timing will have to wait awhile as we are fermenting our wine in the back of the garage. My wife says No diesel smell or exhaust!
So on to more benign jobs.
In replacing the clutch master cylinder I removed the plunger shaft from the pedal arm. Didn't see the alignment mark on the pivot bolt or that it was a cam shape. I couldn't find in manual what that mark lines up with? Do you or anyone know which way it points? Also the cam sleeve extends out about .063 on one side. I think that side goes toward the bolt head?
Looks like I'll be working on clutch and brakes for awhile do to wine making. not a bad distraction.

[charliep]

I had the same sticking problem with OM621 injection pump and had to pull the barrels out of two ports in the pump. I looked down into the holes where the barrels came out and did not see a key or any way to align them according to the slot on the barrel. So I just put them back in and they seemed to seat just fine. But now I am worried that the side port in the barrel won't line up with the slots on the plunger. Am I missing something?

[charliep]

Mystery solved! Luckily I had an extra injection pump to mess with. I carefully extracted a barrel out of one of the ports and observed which way it came out. There is a small locator pin down in the port which fits in the notch of the barrel. On my other pump the pins had been pushed in when I inserted the barrels the wrong way and tightened them down. So I tapped the pins back in place with a small drift punch from inside the rack chamber. Looks like everything is going to be OK now.