Timing adjustment methods - Page 18 - PeachParts Mercedes-Benz Forum

winmutt · #**256** 03-03-2011, 09:47 AM

The best way I have found so far for timing the IP is using the lock tool on the RIV port. Hands down best $30 tool I have bought in a while.

To clarify for certain webmasters around here. This is not the RIV tool, its the LOCK tool for the RIV port. Set the engine at the appropriate angle, unlock the IP, rotate until you can see the tang in port near middle, insert tool, wiggle until it the tool locks in place. DONE.

No stupid drips, no stupid well methods. I did this on the 87 2 weeks ago and it took all of 5min after the the IP was loosened.

leathermang · #**257** 03-03-2011, 11:08 AM

Quote:

Originally Posted by Army

Or discrepancies in transducer performance, or or or or...

=> Go for it Greg!

(@Greg - was that PM of any use?)

Army,
I think it clarified that I would have to buy the report in order to see the material we were discussing.. that I did not simply miss finding it in my search.. thanks, Greg

babymog · #**258** 03-03-2011, 11:10 AM

The lock method is simple, but how accurate?

On my new engine, I set the timing indicator on the front myself with a dial-indicator on the #1 piston, so I know that that is correct. On an older engine who knows if it is correct, especially if the timing cover has been removed at any point.

Further, how accurate is that tang for the start of delivery after 200,000 miles or more? As the IP cam and followers wear, the clearance is greater and it seems that the timing would be delayed by the plunger closing the inlet port slightly later. This possibility would favor the drip method over RIV on a used pump.

Does anyone here have any bench experience that would indicate if and how much delay is in an older pump?

leathermang · #**259** 03-03-2011, 11:47 AM

Quote:

Originally Posted by winmutt

.....No stupid drips, ......

Just as an exercise in the philosophy of mechanicing and machines....
Sometimes a procedure has benefits beyond what is obvious on the face of the instructions.... and the drip method may be one of those....
It has the potential for IGNORING some other things ( wear perhaps, wrong setting of some other relationship IE, chain to IP ? ) which might not be AUTOMATICALLY compensated for with other methods which assume condition and position of a number of related items...
The drip method ignores some or all of those potentials.... and allows one to set ( in a very low tech way... read ... away from home ,no special tool in tool box, etc ) the start of delivery for the IP.. pretty darn close... since the size of the same fluid ( diesel ) DROPS is a fairly stable constant ( redundant wording for effect ) it means that knowing it might get you home in a pinch some time... when other methods would require a TOW or something else... ( they shoot lame horses in the head )..

leathermang · #**260** 03-03-2011, 11:51 AM

Quote:

Originally Posted by babymog

... This possibility would favor the drip method over RIV on a used pump....

I started my post at 10:10 and then went and had breakfast... so I did not see your post in between times... obviously I agree totally.

winmutt · #**261** 03-03-2011, 01:05 PM

Quote:

Originally Posted by babymog

The lock method is simple, but how accurate?

On my new engine, I set the timing indicator on the front myself with a dial-indicator on the #1 piston, so I know that that is correct. On an older engine who knows if it is correct, especially if the timing cover has been removed at any point.

Further, how accurate is that tang for the start of delivery after 200,000 miles or more? As the IP cam and followers wear, the clearance is greater and it seems that the timing would be delayed by the plunger closing the inlet port slightly later. This possibility would favor the drip method over RIV on a used pump.

Does anyone here have any bench experience that would indicate if and how much delay is in an older pump?

Considering that MB uses the AB light I think you are over thinking it. 3 degrees (+-1) allows for alot of wear I would imagine. 87 has 300k on it. Runs like a champ now and no more cold morning smoke outs.

Stretch · #**262** 03-03-2011, 01:23 PM

Quote:

Originally Posted by leathermang

Army,
I think it clarified that I would have to buy the report in order to see the material we were discussing.. that I did not simply miss finding it in my search.. thanks, Greg

Hi Greg - if you are opposed to the idea of previewing the information then you might be able to get a copy via your local library. I think it is well worth the effort involved - but don't just take my word for it take a look at the opinions of others:-

http://www.superturbodiesel.com/std/om617-sae-paper-t-650.html

http://www.superturbodiesel.com/std/how-much-power-can-a-300-hold-t-1867.html

http://www.superturbodiesel.com/std/archive/index.php/thread-70.html

etc etc etc

funola · #**263** 03-03-2011, 01:31 PM

Quote:

Originally Posted by Army

I'm guessing steady readings on your voltmeter are probably more to do with the dynamics of the voltmeter rather than the output from the glow plug. As for your comment about noise - I don't go along with that - sorry (but I see little point in butting heads over it!)

So keep up the good work. You are more than a few steps ahead of me on this project - I'm still scrabbling around in the ditch trying to get some equipment...

I woudln't call it butting heads, just difference in opinion. Note that on mechanical EGT gauges, the thermocouple voltages drive the meter movement directly (no amplifier). Thermocouple voltages are also very low (in the milli volt range like the glow plug), and very low impedanc (essentially a dead short).

I was using glow plug #1's 12 mm hex as a common ground for all 5 glow plugs via an alligator clip. I need to check if that was the problem. Maybe make a better ground connection at each glow plug and see if that resolves the high / low readings on #2 & 5.

Other observations:

While the engine is idling, DVM reads -0.008 volt. Shut the engine off, it goes to 0.0 volts within 1 minute

I noticed that there is a milli volt scale on my meter that gives one more digit of resolution so I'll be using that scale from now on. I was using the volt scale and selecting the lowest range. On the mv scale I am seeing -8.3 mv (- 0.0083 V) at idle, I cracked the injector nut, got a rougher idle, and noted the voltage immediately decreased to -7.8 mv.

Stretch · #**264** 03-03-2011, 01:48 PM

Quote:

Originally Posted by funola

I woudln't call it butting heads, just difference in opinion. Note that on mechanical EGT gauges, the thermocouple voltages drive the meter movement directly (no amplifier). Thermocouple voltages are also very low (in the milli volt range like the glow plug), and very low impedanc (essentially a dead short).

I was using glow plug #1's 12 mm hex as a common ground for all 5 glow plugs via an alligator clip. I need to check if that was the problem. Maybe make a better ground connection at each glow plug and see if that resolves the high / low readings on #2 & 5.

Other observations:

While the engine is idling, DVM reads -0.008 volt. Shut the engine off, it goes to 0.0 volts within 1 minute

I noticed that there is a milli volt scale on my meter that gives one more digit of resolution so I'll be using that scale from now on. I was using the volt scale and selecting the lowest range. On the mv scale I am seeing -8.3 mv (- 0.0083 V) at idle, I cracked the injector nut, got a rougher idle, and noted the voltage immediately decreased to -7.8 mv.

Sorry funola - I didn't mean to be rude - I'm a bit cautious about having a different opinion (even a very slight one) on this thread; considering what has gone on before.

Very interesting indeed that you measured an immediate change when you artificially changed the "engine efficiency" - for want of a better expression - which will probably raise some eye brows!

Like I said before keep up the good work - if I can get hold of the equipment I want, I plan to make some measurements that can be plotted out as voltage with respect to time...

...as for your glow plugs are they still attached as normal to the glow plug relay or have you disconnected them for these measurements?

funola · #**265** 03-03-2011, 02:10 PM

Glow plug connector unplugged from the relay and a male pin inserted into each of the 5 terminals for the measurement, one at a time. Where and how I hook up the ground needs to be improved. Once I rig up the 5 position rotary switch, I will be able to monitor it at speed. Depending on further testing, I may need a 2 pole, 5 position rotary switch and switch the ground also.

funola · #**266** 03-03-2011, 02:27 PM

Here's a pdf of Type K thermocouple reference voltages. I believe most EGT probes use type K's.

http://www.omega.com/temperature/z/pdf/z218-220.pdf

Here are 2 data points

@ 0 F, V= -0.692 millivolt

@ 2500 F , V= 54.856 millivolt

gsxr · #**267** 03-03-2011, 03:48 PM

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.

The Mercedes shop manuals are split into several volumes... one engine, one climate control, one electrical, and usually two for chassis/body. The print manuals have been unavailable new for years, but you can find them on eBay (for a small fortune).

Click here to see one that just sold for cheap... that's what you're looking for, assuming you have an 82-85 OM617 turbo.

There are also the manuals available on CD-ROM,

click here to see what it looks like. Basically it is the printed manuals scanned into PDF format with a really bad Flash interface / menu. Fortunately someone came up with a much better menu that you can use with the discs, click here to download the appropriate one. Note that the Indexes are just that - you still need to buy the discs to use with the nice HTML index.

About the IP timing methods. If you have a pump with the RIV port, that is the easiest / best method to use, preferably with the A-B light box, or the lock tool (in a pinch). Pumps without the RIV port have to use the "wet" methods (drip/bubble) unless you have an inductive pickup light system AND know what specs to use, as the numbers will be totally different from both the factory methods.

leathermang · #**268** 03-03-2011, 03:48 PM

Quote:

Originally Posted by funola

....... I will be able to monitor it at speed.....

What will you be monitoring exactly ?

I pm'd you with the OCD helpline number... did you get it and call it ?