606.910 Correction of Injection Pump timing

[JRImrie]

This may be a stupid question but there are no stupid questions right? I was looking at Sixto's picture, which is excellent by the way, and was thinking.
I resealed my injection pump and reinstall it unfortunately it is too far out of time to adjust. Instead of pulling the injection pump why not pull the timing gear to make the adjustment? The injection pump has indexes on it for the timing. The timing chain can be marked easily and all it requires is pulling the vacuum pump. Please comment even if it is you are crazy.

[GregMN]

Easier to R&R the pump then the gear.

[JRImrie]

I do not see the removal of the gear as more than an hour. R&R the pump is at least a 6 hour job. What am I missing? You did not elaborate as to why can you tell me a little more?

[sixto]

The problem I see is that you have to move chain slack from the tensioner rail to the pump. Doing so means advancing the cams relative to the crank. I don't know how much you can turn the cams before valves hit pistons. You can pull the cams to protect the valves but that sounds like more work and more risk than pulling the IP.

The moral of the story is don't button up the IP until you confirm IP timing

Sixto
MB-less

[JRImrie]

I did check it. It is beyond me why it is not in time, it's close but there is not enough room to get it correct. I did not check the engine setting but the injection pump was right where it should be after turning it over right in the middle it almost can't be any place else.

[Diesel911]

Originally Posted by JRImrie

I did check it. It is beyond me why it is not in time, it's close but there is not enough room to get it correct. I did not check the engine setting but the injection pump was right where it should be after turning it over right in the middle it almost can't be any place else.

It may be th problem is that while the IP is timed to the Crank Damper it still has to be timed on the Correct Stroke.

Assuming the Timing Chain remained in place you should be able to line up the Camshaft Gear Timing Mark and look down at the Crank Dampner and have it be close to OT (Top Dead Center). If the Chain is used I would not expect it to line up exactly on OT.

Then you can turn the Engine in the direction of rotation past TDC to 15 degrees after top dead center. When that is done when you remove the Plug on the timing port you should see the Blade centered in the Timing Port hole. If not you will know for sure you are not timed correctly.


The other issue could be in the last several Years more then a few People have manged to pull up the Element Barrels above and out of their alignment slots when they changed the Delivery Valve Seals.

Some pics in this thread.
OM606 Injection timing

[sixto]

If JRImrie removed the IP and reinstalled it without turning the crank or IP, it shouldn't be out of phase. It should only be off by "a little."

JRImrie, when you center the tang in the RIV port such that you can fit the locking tool, what do you read on the crank pulley?

Sixto
MB-less

[Zulfiqar]

before you go about setting the timing there is one little irritating thing on the 606.910 engine which is the pointer that points to the degree markings on the crank pulley. If you are positive that is 100% perfect then you can achieve the most accurate timing.

To index it back (if you lost the indexing) - e.g. if you removed it without referencing the pulley then a special tool is required in place of the combustion chamber and a dial gauge mounted in it to read the piston height. I did that mistake and luckily did not clean the scale good enough - I found the old shadowed screw head mark in the grime and oil stuck to it to install it correctly. There is also a way to confirm the accuracy, it speaks of locating the protuding pin dead centre in the hole where the special workshop tool to measure engine rpm is attached to - its viewed from underneath - at 20 degrees advance it should be perfectly centered in the hole - MB tell you to use a special tool that slides in - eyeballing and using some calipers I sort of verified it was correct (too much time at hand that day)

[sixto]

Originally Posted by Zulfiqar

... a special tool is required in place of the combustion chamber and a dial gauge mounted in it to read the piston height.

Zulfiqar means Precombustion chamber

Sixto
MB-less

[Zulfiqar]

sorry yes - the precombustion chamber

[GregMN]

Originally Posted by JRImrie

I do not see the removal of the gear as more than an hour. R&R the pump is at least a 6 hour job. What am I missing? You did not elaborate as to why can you tell me a little more?

set crank to 15 degrees after TDC
install the IP locking tool ( which you cannot do if the timing is off as much as you say it is )
remove the IP timing gear's bolt ( left hand threaded, turn clockwise to loosen )
remove the hard lines to the injectors
Remove the valve cover ( you might have to remove the injectors to get the cover off, I have not removed my VC, so I am not sure )
zip tie the chain to the cam sprocket
Lock the cams in place
remove the cam sprocket from the cam
remove the chain tensioner
use a thin strip of metal or plastic to move the chain off of the IP timing gear's teeth ( it will be hard to get enough clearance to do this without removing the IP shaft from it )
remove the IP timing gear and reinstall in the position you think will correct your problem

(since you could not lock the IP in place, you will have a hard time guessing where to reinstall the timing gear. If you can remove the gear, then you need to try to get something on the IP shaft to turn it to it's locking position and get it locked, without ruining the splines on the IP shaft )

re assemble everything and test the timing

did it work ? if not repeat

as I remember, you cannot get enough slack on the chain to slip the gear off the IP shaft. you have to be able to get the slack of the chain and be able to move the gear toward the engine to get it free of the chain and out.

You can screw up the timing of the cam during the procedure. The problem is that the cam should be locked at TDC and the IP can only be locked at 15 degrees after TDC. The IP's at rest position is not at it's timed/lock position. It will move off of it's timed/lock position if not held/locked in place.

If you do choose to try to remove the IP timing gear to adjust the IP timing, please take notes, and photos if possible, and report back to the forum.

[sixto]

Originally Posted by GregMN

Lock the cams in place

How do you do this at 15*ATDC?

Originally Posted by GregMN

remove the chain tensioner
use a thin strip of metal or plastic to move the chain off of the IP timing gear's teeth ( it will be hard to get enough clearance to do this without removing the IP shaft from it )

How to you get chain slack from the tensioner side to the IP side? The cams are locked so you have to turn the crank CCW. Can you gain enough slack to separate the chain from the IP timer before pistons touch valves? The safe bet is to pull the cams... or read the FSM if it has something to say about it

Originally Posted by GregMN

remove the IP timing gear and reinstall in the position you think will correct your problem
(since you could not lock the IP in place, you will have a hard time guessing where to reinstall the timing gear. If you can remove the gear, then you need to try to get something on the IP shaft to turn it to it's locking position and get it locked, without ruining the splines on the IP shaft )

At this point I'd use the IP timer or heavily padded grips on the IP drive shaft (timer removed) to center the tang in the RIV port and confirm by fitting the locking tool. But first, I'd loosen the IP and set it so the bolts are in the middle of the adjustment slots.

Originally Posted by GregMN

as I remember, you cannot get enough slack on the chain to slip the gear off the IP shaft. you have to be able to get the slack of the chain and be able to move the gear toward the engine to get it free of the chain and out.

I've never done this but I read about slipping a stiff sheet between the chain and timer - giving up positive indexing which could lead to problems later on - all the way around timer where it's in contact with the chain. I also read about heavily greasing the chain and pushing it away from the timer with the grease holding it away from the timer.

Sixto
MB-less

[GregMN]

Originally Posted by sixto

How do you do this at 15*ATDC?



How to you get chain slack from the tensioner side to the IP side? The cams are locked so you have to turn the crank CCW. Can you gain enough slack to separate the chain from the IP timer before pistons touch valves? The safe bet is to pull the cams... or read the FSM if it has something to say about it



At this point I'd use the IP timer or heavily padded grips on the IP drive shaft (timer removed) to center the tang in the RIV port and confirm by fitting the locking tool. But first, I'd loosen the IP and set it so the bolts are in the middle of the adjustment slots.



I've never done this but I read about slipping a stiff sheet between the chain and timer - giving up positive indexing which could lead to problems later on - all the way around timer where it's in contact with the chain. I also read about heavily greasing the chain and pushing it away from the timer with the grease holding it away from the timer.

Sixto
MB-less

You have pretty much made my point that it cannot be done. Thank you.

The cams can only be locked at TDC.

You can get slack beyond the cam gear by removing it from the cam after the cam is locked, which you cannot do at 15 degrees after TDC.

I noted the impossible procedure to make my point that it is easier to R&R the IP than to try to R&R the timing gear, that cannot be done anyways.

[JRImrie]

I plan on doing the job as Sixto suggests without the basket. I will look at the removing the timing gear when I pull the vacuum pump. I think ya'll are right there is not enough slack in the timing chain.The FSM is incorrect on setting TDC for a 606.910. The FSM says to look for the pin punch mark on the 606.910 there is no pin punch mark. If one goes to FSM cam timing procedure you will see that it explains that there is a hole in the cam and the cam tower on the 606.910 to set TDC. The car has been sitting since July due to a family emergency and misc. other problems. I do not remember positively how I set TDC in July. I probably removed the #1 glow plug and felt for the piston and compression since the procedure was wrong and I did not look at the cam timing procedure. I set the timing when I checked it in December using the hole in the cam gear it is very easy to see the hole and set TDC visually. In neither case did I pull the cam cover.
I am really not sure what the index on the injection shaft set at I will check. Why can't you just take the link out of the timing chain and reattach the link?

[GregMN]

Let us know how it went when you get done.

If you run into a problem, just ask for help.