Timing adjustment methods - Page 4 - PeachParts Mercedes-Benz Forum

leathermang · #46 01-15-2011, 11:47 PM

Seat of the pants comparisons between different positions of the IP timing are very hard to quantify unless one has access to a dyno....

The question then becomes... is there a limit to the setting parameters which could do damage to the engine but feel ok by the seat of the pants... where leaving it there might cause real damage ? I am thinking about such things as burning holes in the tops of pistons...

ForcedInduction · #47 01-16-2011, 11:24 AM

Quote:

Originally Posted by scottmcphee

and it's fixed

Not it isn't. Static timing only sets the base, the timer device in the chain sprocket can vary timing by up to 8* depending on engine load and acceleration.

scottmcphee · #48 01-16-2011, 03:34 PM

Quote:

Originally Posted by leathermang

Seat of the pants comparisons between different positions of the IP timing are very hard to quantify unless one has access to a dyno....

The question then becomes... is there a limit to the setting parameters which could do damage to the engine but feel ok by the seat of the pants... where leaving it there might cause real damage ? I am thinking about such things as burning holes in the tops of pistons...

Has anybody on this board ever melted a piston on their MB car with the stock IP fueling system? (Doesn't count if your crankcase oil was too low...)

You would hear terrible pinging before that ever happened. Your ear will tell you not to set timing there.

leathermang · #49 01-16-2011, 04:24 PM

Quote:

Originally Posted by scottmcphee

Has anybody on this board ever melted a piston on their MB car with the stock IP fueling system? (Doesn't count if your crankcase oil was too low...)

You would hear terrible pinging before that ever happened. Your ear will tell you not to set timing there.

We never get really good forensic tear down reports ..so there is no way to know what variables were extant when those who posted pics of melted pistons were still driving along.

scottmcphee · #50 01-16-2011, 04:54 PM

Quote:

Originally Posted by ForcedInduction

Not it isn't. Static timing only sets the base, the timer device in the chain sprocket can vary timing by up to 8* depending on engine load and acceleration.

I stand totally corrected, thank you.

It appears the timing device has both counter weights and springs, which means it must compensate for rotational speed and acceleration. Cool.

paddo · #51 01-17-2011, 05:09 PM

Quote:

Originally Posted by Diesel911

The thumping is most likely being caused by the Motor Mounts and Transmission mounts and maybe the Engine Shocks (if you have them).
Have someone crank your Engine and see of the thumping is caused by your Engine Block being jerked to one side.
If the thumping is coming from the Air Filter housing there is some threads on how to deal with that.

There is more than one thing that can cause the Ratteling Sound.
If it rattles after starting and the ratteling goes away after the Engine ie warmed you could have a Glow Plug Issue. Easy to check them with an Ohm Meter
Things that you can do yourself without spending much money are a Valve Adjustment and the Timing.
After that it is an Injector or Compression issue and maybe Camshaft Timing late due to Timing Chain/Gear wear.

I recently replaced a damaged motor mount and adjusted the valves, both of which made a huge difference. The thumping doesn't sound like mounts to me, and it sort of starts and stops randomly mainly when cold, so not sure what it is but it hasn't been happening lately (??).so I'm not too worried about it. I also replaced all faulty glows recently so at this stage I think the most likely candidate for the rattling is the timing.
the car is running fine lately, so really my only concern is if the timing is out enough to be a risk of causing engine damage. It would be good to have the engine running at absolute peak but I don't have time or money for that and I'm just happy if it is getting me from A to B reliably.

It just seems that adjusting the timing is a bit more tricky and involved than the other above jobs and the instructions I've read so far don't make it clear how to actually do it, I think they mostly assume prior knowledge of various components. I mean for example, where are the actual nuts or bolts that you actually turn and what do you move to adjust the timing, how do you measure the timing, what is this mysterious drip test etc etc. I guess when I have time I'll go over the posts, read manuals etc but at present it just seems too much of a hassle esp in NE winter. Also I'm worried about making it worse and actually causing damage, I destroyed a motor in my younger days doing just that (on an old merc gasser, I think it was a 220sb 1960's)

Diesel911 · #52 01-17-2011, 05:35 PM

Quote:

Originally Posted by scottmcphee

Has anybody on this board ever melted a piston on their MB car with the stock IP fueling system? (Doesn't count if your crankcase oil was too low...)

You would hear terrible pinging before that ever happened. Your ear will tell you not to set timing there.

I think it was one of our members lost a Piston aparently due to the Spray Nozzle attatched to the Block breaking off.

Other than that I have not read of anyone "Frying A Piston". I have see that on the older 1970s Cummins and Detroit Diesels that were used in Trucks. But, they are direct injection Engines.

I would suspect that damage caused by Injection Timing or bad Injectors would start in the Prechamber first. With either you would have some sort fo symptoms and have ignore the symptoms.

Diesel911 · #53 01-17-2011, 05:42 PM

Quote:

Originally Posted by paddo

I recently replaced a damaged motor mount and adjusted the valves, both of which made a huge difference. The thumping doesn't sound like mounts to me, and it sort of starts and stops randomly mainly when cold, so not sure what it is but it hasn't been happening lately (??).so I'm not too worried about it. I also replaced all faulty glows recently so at this stage I think the most likely candidate for the rattling is the timing.
the car is running fine lately, so really my only concern is if the timing is out enough to be a risk of causing engine damage. It would be good to have the engine running at absolute peak but I don't have time or money for that and I'm just happy if it is getting me from A to B reliably.

It just seems that adjusting the timing is a bit more tricky and involved than the other above jobs and the instructions I've read so far don't make it clear how to actually do it, I think they mostly assume prior knowledge of various components. I mean for example, where are the actual nuts or bolts that you actually turn and what do you move to adjust the timing, how do you measure the timing, what is this mysterious drip test etc etc. I guess when I have time I'll go over the posts, read manuals etc but at present it just seems too much of a hassle esp in NE winter. Also I'm worried about making it worse and actually causing damage, I destroyed a motor in my younger days doing just that (on an old merc gasser, I think it was a 220sb 1960's)

Maybe there is a Member in your area that would allow you to watch when he does the timing.

hesterfoster80 · #54 01-18-2011, 07:48 AM

Quote:

Originally Posted by bplust

where can I get a factory shop manual? all I have is the Haynes, which is helpful, but I would like some more detail. My other vehicle is an 89 Dodge w250 diesel, and I have the two volume factory service manual for it, which is extremely helpful.

it would really be of great help...if someone upload the links to the manual...

whunter · #55 01-18-2011, 11:53 AM

Quote:

Originally Posted by hesterfoster80

it would really be of great help...if someone upload the links to the manual...

Mercedes Service Manual Source, CD/DVD/Paper
Mercedes Service Manual Source, CD/DVD/Paper

.

paddo · #56 01-19-2011, 04:56 PM

Quote:

Originally Posted by Diesel911

Maybe there is a Member in your area that would allow you to watch when he does the timing.

It's OK, I got access to the shop manual info - doesn't look too bad but I'll wait till it's warmer. My other concern is economy which doesn't seem too great at present. I would suspect if the inj timing is badly affecting economy it is reducing engine life also due to misdirected explosive forces? I don't suppose it is as dangerous as a gasser, since fuel only explodes when pressure reaches the sufficient level.

Diesel911 · #57 01-19-2011, 11:46 PM

Quote:

Originally Posted by paddo

It's OK, I got access to the shop manual info - doesn't look too bad but I'll wait till it's warmer. My other concern is economy which doesn't seem too great at present. I would suspect if the inj timing is badly affecting economy it is reducing engine life also due to misdirected explosive forces? I don't suppose it is as dangerous as a gasser, since fuel only explodes when pressure reaches the sufficient level.

While the Fuel Injection Pump and Engine Camshaft Timing (both become late/retarded as the Timing Chain/Gears wear) I believe it is the opening pressure and condition of the Injector Nozzles that has more of an effect on the how well the Fuel Burns.

If the Injectors are not atomizing the Fuel well part of it is not going to burn well.

This is not a DIY on how to time but discussed is some of the reasons that people have trouble with the Drip Timing Method.
Timing adjustment methods

whunter · #58 01-20-2011, 11:22 AM

Drip Timing Threads
Drip Timing Threads

Engine Mechanical:
Engine Mechanical:

Diesel Injection:
Diesel Injection:

Fast navigation Do It Yourself Links
Fast navigation Do It Yourself Links

.

leathermang · #59 01-20-2011, 08:11 PM

Quote:

Originally Posted by Diesel911

While the Fuel Injection Pump and Engine Camshaft Timing (both become late/retarded as the Timing Chain/Gears wear) I believe it is the opening pressure and condition of the Injector Nozzles that has more of an effect on the how well the Fuel Burns.

If the Injectors are not atomizing the Fuel well part of it is not going to burn well.

This is not a DIY on how to time but discussed is some of the reasons that people have trouble with the Drip Timing Method.
Timing adjustment methods

I believe all those things are important....and something which I have not seen mentioned lately with regard to ' atomizing'... is that pintle ( little bar ) which the fuel is shot towards and breaks it up and directs it towards those (7 more or less ) radially drilled holes in the precombustion chamber.. many have opened theirs up to find it burned or corroded away... which may block some fuel exit holes or at the very least NOT atomize the fuel the way MB intended it...

As to getting the IP set correctly.. I have always wondered why MB did not have some screw control adjustment for fine setting of the angle off the block of the IP. Have thought about welding one up myself...it is often SO hard to move... getting it exactly at one drop per second using a two by four or something similar feels less than sophisticated....and everyone knows how important it is to feel sophisticated when working on a Mercedes Diesel....

Diesel911 · #60 01-20-2011, 10:44 PM

Quote:

Originally Posted by leathermang

I believe all those things are important....and something which I have not seen mentioned lately with regard to ' atomizing'... is that pintle ( little bar ) which the fuel is shot towards and breaks it up and directs it towards those (7 more or less ) radially drilled holes in the precombustion chamber.. many have opened theirs up to find it burned or corroded away... which may block some fuel exit holes or at the very least NOT atomize the fuel the way MB intended it...

As to getting the IP set correctly.. I have always wondered why MB did not have some screw control adjustment for fine setting of the angle off the block of the IP. Have thought about welding one up myself...it is often SO hard to move... getting it exactly at one drop per second using a two by four or something similar feels less than sophisticated....and everyone knows how important it is to feel sophisticated when working on a Mercedes Diesel....

I cannot remember if it was one of our members or on another Forum but someone made a tool to rotate the IP that clamped on to the fromt Squarish portion of the Fuel Injection pump.

When I did mine I removed the Fuel injection Hard Lines and I used my largest Channel Locks over the Delivery Valve area gripping the IP housing. With the Handle Pointing towards the Engine.
I gripped the Handles with the Left Hand and hit the Handle with the right had to bump it along a little a time.
It worked out well. The handles are long and there was a lot of leverage so it only took little bumps to move it along.