First of all, it's not an "RIV" locking pin. The RIV tool is an electronic device that does not lock the IP.......it simply measures the point at the exact top of the V notch. The locking pin is inserted in the side of the newer style pumps and can engage the "V" notch in the IP. It's a very poor design and the slot in the tool is about the width of a screwdriver slot.

It's very easy to slide right past the slot and attempting to engage the slot by yourself while turning the crankshaft is nearly impossible.

Once you do get the slot engaged, you can read the crankshaft damper for the IP timing. But, you can't rotate the IP at this point. The tool must be removed, the IP adjusted, and the tool reinserted yet again.

Don't bother with this tool........it's a waste of time.

This morning I talked to a 2nd Bosch Service in another town.
The reaction there was even more disappointing, while the facts (how to adjust what) are clear.
He was less interested in the mV phenomenon than my little sister.
“Maybe it will work…”.
BTW, this is a common behaviour also in other business.
Barry, you were right how you understand my yesterday’s visit at the Bosch.
Back to the mV:
Before touching the elements I had around:
14, 13, 9, 14, 12. This showed me the weak #3. The engine did run well, but I expect an improvement. During adjustment I had the impression of smoother idle and better response. I hope to get the licence plates within the next days (serious trouble with the traffic ministry, fighting for a smaller front plate). Since now I made about 800 miles with “transfer plates” of a car seller.
I am sure that the previous pump just was out of individual quantity causing rough idle. But now it is back from the pump shop and waiting as a spare.

If there is no special mission for me from your side right now I want to learn something about the absolute mV, like mine now approx. 11 on each cylinder. Is this value in relation with the “health status” of the engine? What could be the max. mV? And where is the limit for the resulting temps. before the pistons start melting?
This was one advice of the 1st Bosch boy, melting the piston by too much fuel. Beyond too much he said the temp. would drop. Unburned fuel, because simply too much to burn, will cool down the cylinder.
I will try to get in contact with Bosch engineers for diesel and learn about i.e. injected quantities with tolerances and how much this changes when I turn the element form one extreme to the other. Or, now I start dreaming, taking a mV adapted pump to the shop and check the quantities, compare with specs and with these results I could see if the adaptation was fine tuning (when within specs) or even the engine is worn (when mV is equal, but the necessary quantity is far off specs) or something else.

Sam, I promise to take lessons instead of adding german writing

Tom

Tom, the ideal of the pistons melting was in refference to a cylinder with a larger compression drop than 2 bar being corrected. Perhaps say 6 bar different for example might be bad. Or perhaps a element out of sequential timing advanced too far. Or the whole pump advanced too far in relation to the engine. We will be able to measure the exact internal flame temperature within 40 deegrees F or perhaps 20 degrees C soon I hope although that remains to be seen. A gentleman on another site Has worked this out. We will have to try to contact him and see if he will participate on our site. His name is crossbones on the site mentioned in post #120 on this thread. Have a look yourself. It is well worth reading. I hope he will participate as his large knowledge is needed. My hope is he has people very interested on our site to involve himself with even if some like myself are a little backward in comparison. At least we have the same interests I believe. Plus he would be aware this should be done. If you have not read what is eventually possible read his posts. Your original glow plug readings where really all over the place. The indication of a healthy well running engine is more the simularity ( or sameness) of voltages rather than the amount. We will all together make a manual of instructions to use this system for everybody after awhile. This will help make misteaks almost impossible. Plus allow everybody to use and understand what they are doing. It will be a challenge to do this. I personally want to see guys like you, Kevin, Sam and Mobetta plus many others involved in it as you are now. I was glad to hear your idle was smoother as well. In theory your engine should perform a little better too. Just keep being involved and posting. Your input has been great and very helpful to all the people reading this thread. Already you have expanded possibilities a lot. Thanks.

Tom, on that now spare pump you just got back. Perhaps the people at the shop might tell you if the quantity of fuel per element was out before they balanced it. You might like that information as well for refference. If it indeed was the reason the pump was not proper. They should remember. Just a thought.

Found another post that talks about the advance for the 123 diesels is part of the mechanism that also operates the vacuum pump...centrifugal force weights that advance the pump with rpm increase.....kevin

I still had some questions on the 240D so I did the following tonight.....Took all the injector lines off...freed the pump and pushed it to the full advance stop toward the block...the drip method showed this to be 30 deg. BTDC...linkage starts getting in the way this far forward...then....pulled the pump to the full retard stop position...drip method again showed this to be ~17-18 deg. BTDC....noticed that the pully is marked starting at 80 deg. BTDC....but there is only about a 12 degree range available with pump movement.....between 18deg. BTDC to 30deg. BTDC.....This was the true drip method not the well-up test which my IP guy says is sloppy timing at best because of something in the IP valve tensions.....put back together and peaked the mv's @ 6.5.....any further pump rotation did not result in any more mv's...6.5 held steady as far I could push it...almost on the full advance stop....looks like a mv plateau is reached which seems like the place to stop when further pump rotation advance results in no further increase in mv's....this dividing line or threshhold on my 240D is right at 24~25 deg. BTDC...which is spec....important to watch for the begining of the no change state as you could take the pump into more advance than wanted.....I think this is what Barry was describing earlier....Did not get to the 300D but may take off work again to get more data on these things....interesting thing was the lower overall group read from the other day....tonight peaks =6.4 to 6.5 mv....the other evening 6.9 to 7 ....air temp?...humidity? phase of the moon?...everything else was the same...meter and all....car has not been moved since last test.....squeezing the inj. lines to get pump in advance position helped a lot with the dynamic movement of the pump...had more range....really need a lever like Sams idea to move this thing even with all nuts & bolts finger loose ....left the timing a wee bit advanced from my original mv setting peak just to tinker...prob about 25 deg. by drip method.....drip method gets easier each time I do it...getting right snappy at it!....Back on the 300D this weekend hopefully....kevin

and if I remember correctly that you had installed a new timing chain etc in the 240D... if this is correct, I'm not at all surprised that your mv timing was right at 24 Deg. BTDC. If we can get more confirmation of this result, then we will be on our way to proving Barry's mv timing method to be valid for these vintage MBZs.

Your 300D results might turn out a little different because the timing chain was not replaced (?) and you figure it has how many miles on it?

Did you use the new special set of fuel lines you talked about having made up by your friend at the Diesel Injection shop... your Bosch certified technician friend?

Now if I can get a handle on this "Tach-N-Time" meter so that we will be able to use it quickly with close to comparable accuracy as you had with your "drip" timing measurements!

If you would like, I think I can get my hands on the official MBZ descript of the "drip" timing method !
Regards,
Sam

Brain Carlton has correctly pointed out to me that these are two different tools but my interest is that the pins have the potential to set/check IP timing just the same as the far greater expensive R.I.V. light instrument.

Take a look at my attached, revised, file on this subject… and NOTE the similarities in the part numbers of two of the three items. The people at Braum say that it is just that they are “mimicking” MBZ’s numbers!

Also interesting is that if you call your MBZ dealer’s parts department they will not be able to give you any “application” information [ what models/engine they will work on? ]… and that is my greatest complaint about this AutoGiant… they canNOT or will NOT provide us with readily available information about their own parts/tools… information that is crucial for us DIYers. If Toyota ever decides to pander to us DIYers, watch out MBZ… and IF they decide to market a modern but simpler diesel automobile with us DIYers in mind, this could be the end of much of MBZ’s and VW’s automobile production!

I believe the “Early Model” Baum “Injection Pump Lock Pin” should work on both of my 1980 model MBZs so I’m ready to invest $50 to find out. If it works and we are able to quickly check the timing alignment of the IPs on the 615, 616, some of the 617, and 621 engines as their application notes show, then I will be happy and we would then purchase the other lock pin for the later model engines/IPs.

Where would this leave the "Tach-N-Time" meter instrument... well as I see it, these same lock pins will hopefully help us build credibility in the meter and once we can rely on results from the meter, then it's minimal time requirement make it preferred over the lock pins... at least for many/most cars that come through the shop's door!

Regards,
Sam

Kevin great post, I suspect the difference in mv readings was possibly created by a difference in humidity and air temperature. Actually creating a slightly different idle speed. Change in idle is equivelent to different voltages needless to say. I have been well aware of a phenomona for years now but am at loss to find a way to take advantage of it. Might try to stimulate my lazy brain a little later as it does impact milage greatly. Rather than check our method against what Sam presently has perhaps we can calibrate his pizeo sensor and amp from the milli volt method. Who would have ever thought this potentially possible even a short while ago? Sorry Sam just could not help it but all in fun. Now for the 300d. If the chain is well stretched and the cam has not been corrected to compensate it gets interesting. I would not expect the drip method and milli volt method to equate as well as your 240 but it might. Talk about hedging your bets. We are entering the area of custom timing that reflects the actual condition of the engine. So it might work out the same as the 240d but do not count on it for sure. Does not mean anything is wrong as then the milli volt timing is vastly superior in practical terms. It will be compensating for the cam being out. Really just a comprimise but better for the engines performance. Kevin you have basically spent the time to prove the concept and you were succesful. Fortunatly a lot of guesswork by many people has worked out exceptional well so far. .One aspect of dealing with these engines has probably changed forever. Hope we will continue to be as succesful with many other approaches. Kevin, I had to wonder when I did the first volkswagon if the plateau might resolve with instruments capable of 1/100th milli volt. But think as originally suspected might just be overkill. This should probably not be examined for say six months when we will know a great deal more I think. Again a well done guys. I also think Kevins results are well worth the twisted path and many posts to have gotten to. The people reading this thread have got to be aware it does not get any better. From concepts to conclusions. It could have so easily worked out otherwise. Or have been lost to history by people like Kevin and Sam not participating. I suspect more interested people will materialise with further applications experimentation.

[I put up a POST earlier with the same title and it was suppose to have a file attached... but there was no file. This is to try again:]

Brain Carlton has correctly pointed out to me that these are two different tools but my interest is that the pins have the potential to set/check IP timing just the same as the far greater expensive R.I.V. light instrument.

Take a look at my attached, revised, file on this subject… and NOTE the similarities in the part numbers of two of the three items. The people at Braum say that it is just that they are “mimicking” MBZ’s numbers!

Also interesting is that if you call your MBZ dealer’s parts department they will not be able to give you any “application” information [ what models/engine they will work on? ]… and that is my greatest complaint about this AutoGiant… they canNOT or will NOT provide us with readily available information about their own parts/tools… information that is crucial for us DIYers. If Toyota ever decides to pander to us DIYers, watch out MBZ… and IF they decide to market a modern but simpler diesel automobile with us DIYers in mind, this could be the end of much of MBZ’s and VW’s automobile production!

I believe the “Early Model” Baum “Injection Pump Lock Pin” should work on both of my 1980 model MBZs so I’m ready to invest $50 to find out. If it works and we are able to quickly check the timing alignment of the IPs on the 615, 616, some of the 617, and 621 engines as their application notes show, then I will be happy and we would then purchase the other lock pin for the later model engines/IPs.

Where would this leave the "Tach-N-Time" meter instrument... well as I see it, these same lock pins will hopefully help us build credibility in the meter and once we can rely on results from the meter, then it's minimal time requirement make it preferred over the lock pins... at least for many/most cars that come through the shop's door!

[I see the file as I compose... so let's "Submit Reply" and see what happens]...
Sam

Attached Files

RIV Research File-2.doc (39.5 KB, 246 views)

Take a look at this POST on a FORUM for VW TDI enthusiasts:
http://tdiclub.com/articles/A3-TimingBelt/
And be sure to browse through the many, many, photos and count the number of times the word "Remove" or other equivalent verbiage is used!

Count your blessings that we are hooked [auf Deusch..."angespannter"? like an "Süchtiger"] on these old MBZs... with relatively open and exposed engines!

Sam

Hello All...Here we go....Got to the 1978 300D tonight...I had it peaked by the millivolt method a few days ago....It has sat there since ...tonight I did the drip test before doing anything...same setup...spring and valve out of #1 element...drip tube attached...vacuum line detached from shutoff valve...IP lever wired in full load position....cam lobes up ....I do not know where this timing was set before all this ...only thing done was to peak the MV readings at idle like I said.....the IP remained locked where I set it a few days ago....While pumping the fuel pump gently and rotating the crank clockwise from the front starting at about 50 deg BTDC....slowly slowly...got to the point of rotation where the fuel just dripped before complete stoppage....I was not looking at the degree marks as I turned crank.....the area of rotation critical to begining of delivery is not so much movement of the crankshaft but just pressure being held by your arm on the wrench...not enough movement to see at this point...just feel the small pressure opposing rotation of the crank....just watch the drips...pull a little harder on crank...drips stop...relax pressure on wrench a little bit...drips increase to tiny small stream....no noticable movement at all of crank....stopped when I had it stable and looked at the degree marks under pointer...23.5 to 24 degrees!!

The MV method has scored again!...After this I had to check timing chain stretch so i could sleep tonight....removed rocker cover and rotated crank while watching factory hash mark on cam...made damn sure it was perfect with the mark on the cam tower...used my close-up eyes....sure enough crank pulley 3.5 deg of stretch past the 0 TDC mark...possibly approaching 4 degrees.....this did not seem to change the millivolt and drip methods agreement any..??
So there we have it... both my diesels when set with the MV method alone is so close to the drip method that I cannot see any difference even with a worn or new chain...I must digest this for a while....The old "78" 300D is about to get a chain..brand new IWIS on my kitchen counter in the box just screaming to be put on...But the thing cranks and runs so well...the average joe would leave well enough alone...but the average joe is not obsessed with these things......Any thoughts..??..kevin

so based upon the results from your 300D's drip timing check, chain stretch does not affect timing.

Q1 - [anyone] Does this mean the hydraulic tensioner compensates? I think the 4 Degrees Kevin found is the maximum MBZ recommends?

Q2 - When you [Kevin] last set the timing on these engines [ before drip test timing checks ], did you have 1 VOM connected parallel to all plugs or multiple VOMs on each plug?

Great news... “chaulk one up for the team” [die Mannschaft hat gewonnen ] !

OK Barry, where do we go from here? Where next ‘ol fearless leader ! ?

I have just ordered the Baum [ good Irish name ! ] Injection Pump Lock Pin (p/n 900-8673) which is suppose to work 615, 616, early 617, and 621 engines. I hope this will allow me to check the accuracy of my “Tach-N-Time” meter so that in the future we can more easily double check timing after an engine has been adjusted using the IP " mv timing method " !

Best regards,
Sam

Sam....I think the Chain stretch the IP sees is 1/2 of the total since it is a 1/2 time device like the camshaft...that is what I understood of someones description of the process....2 revolutions of the crankshaft per 1 revolution of the camshaft & IP....I do not have enough sense to think this out....
I set the IP advance with the meters hooked up to all the glow plugs (parallel) since all the glow plugs in both cars are new there was not much difference in the individual plug readings...The glowplugs in the 300D are the upgraded Bosch type (large body pencil parallel#80035) replaced the large body (series) type..... you would not believe the cranking difference!) ....240D plugs are Bosch small pencil parallel....both cars set with the mvs at the beginning of the mv plateau....when I put the new chain on the 300D I will recheck all the timing to see if I have to move the pump... will check with both methods....I wish I could come up with a way too get more dc resolution on the O-scope...I need a voltage multiplier probe to use the scope trace as a setting indicator...not the X 10 probe...that is actually a divide by 10 probe..which allows you to see larger voltages than with the X1 probe...we need to see smaller voltages..I use the scope trace as one would a needle on an older type voltmeter..as I am peaking the IP...the horizontal trace rises vertically with the mv increase....problem is the scopes smallest volt per division setting is 5 millivolts per vertical centimeter..not enough to see the small changes.......A small signal dc amplifier probe...?..help! anyone...?...kevin

and first I have a question below about what you mean during the mv timing procedure... where you say "... the beginning of the mv plateau...".

Q1 - By this do you mean as you advanced the timing and you were rotating the top of the IP towards the engine... at the beginning of the peak mv reading as you were doing this?

Q2 -Also did you say you were able to take out some of the "fuel line spring" by counter-bending each of the fuel lines one at a time, this anticipating that you would need to advance the timing a small amount?

Q3 - And finally, am I correct that you used the tool you made that was attached to the front of the IP... you used this tool for these last mv timing adjustments... and assuming this was the case, how long was the pivot handle? As I see it the longer the handle, the better, for lenght also makes it easier to more precisely adjust for that start of the peak mv plateau.

Regards,
Sam