Setting pump primary timing by milli volt method. - Page 2 - PeachParts Mercedes-Benz Forum

barry123400 · #16 05-08-2006, 02:54 PM

First thing is to get those two electronics parts to get rid of the hunting effect.

Call the assembly a voltage or voltage hunting stabilizer.

You will be amazed how the hunting or drift stops and the final digit remains stable.

Next is to start adjusting the number one or two elements till the voltage on one of them is the same as on 3,4,&5.
Of course as soon as you start to adjusting the number one or two element # 3,4,&5 will start to change their voltage as well.
Your object is to keep at it till both voltages are the same.

That is why a second set of hands is a good ideal.
He can read back and forth at your suggestion while you are adjusting the element.
As soon as that is done do your next element the same way it will be either #1 or #2 of course depending on which one you did first.

When all five voltages are equal your job is done.

Absolutely does not matter what your final number is only that they are all the same for practical purposes.

Of course do not adjust #s 3,4,&5 elements at any time.

When you have accomplished that then we can do the overall timing of the injector pump to engine.
If you feel you want to but may not even be required.

Ask for clarification of any thoughts you have.
I will try my hardest to deliver understandable answers. .
Edit: Just re read your post.
It does not matter if you go higher or lower in voltage to match the voltages of 3,4,&5.

The object is absolute here and that is to make 1 & 2 the same as 3,4,&5.
But do get the two electronic type parts and add them to simplify your job.

It's gone on so long now one or two days are not going to matter and I want you relaxed.

Also as we go along other people will be watching and learning something from your experience.

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Old300D · #17 05-08-2006, 03:57 PM

What does the glow plug voltage represent? Why do you try to set the highest value?

barry123400 · #18 05-08-2006, 04:16 PM

Highest combustion temperature is present at the highest voltage.

Fuel injected at that point or lets say the bulk of it should give maximum energy output to engine.
Or maximum utilization of fuel if lucky.
Certainly the most available power.

Old 300d, this applies to the direct relationship of point of fuel introduction.

Not to be confused with what the gentleman is trying to accomplish with his pump out of sequential time.

Hope he ignores it for the time being.
Others may put it more succinctly.

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Old300D · #19 05-08-2006, 04:43 PM

Quote:

Originally Posted by barry123400

Highest combustion temperature is present at the highest voltage. Fuel injected at that point or lets say the bulk of it should give maximum energy output to engine. Or maximum utilization of fuel if lucky. Certainly the most available power.

Old 300d, this applies to the direct relationship of point of fuel introduction. Not to be confused with what the gentleman is trying to acomplish with his pump out of sequential time. Hope he ignores it for the time being. Others may put it more succulently.

Thanks, that's what i figured, but I didn't see it spelled out. Have to ask the obvious.

barry123400 · #20 05-08-2006, 05:17 PM

Old diesel, I am not a know it all.

Sometimes my answers will be wrong.
Why I hope this will totally work out is that I feel I should contribute something of some worth to the members that follow this site.

You have all freely given me so much.
I will in concert with others try to take this to the maximum practical applications.
It is the best potential thing to help people keep the ownership costs down and improve ease of service as information is gathered.
You also will not have to be a rocket scientist to apply it either.

What really concerns me is that I also have the faint outline of something else in mind not related to the above.
But might be practical as well.
Will have to wait to see how this goes first.
See many applications not even even mentioned yet for the millivolt system.

Right now it is gathering data and dealing with any modifications that are required plus supporting users that must have attention as they arise.
Every successful conclusion is going to give it a boost till it becomes the preferred method if possible.

Also it was only partially in jest.
A manual will have to be developed for complete utilization of the system down the road I think.
Right now we are just playing around the edges.

boneheaddoctor · #21 05-09-2006, 08:27 AM

I'd like to see the timing that has the highest reading verified by checking it after the fact with the RIV tool to verify just what amount of advance was really achieved and how close it is to spec. That will give this method credibility. and back it up by doing the same on two other cars.

Brian Carlton · #22 05-09-2006, 08:35 AM

Quote:

Originally Posted by boneheaddoctor

I'd like to see the timing that has the highest reading verified by checking it after the fact with the RIV tool to verify just what amount of advance was really achieved and how close it is to spec. That will give this method credibility. and back it up by doing the same on two other cars.

I'm interested in this myself. I might just give it a try on the SD with the RIV lights.

It's entirely possible that the current FSM spec is a compromise for emissions. Further advance of the injection timing might provide some benefits.

Pete Burton · #23 05-09-2006, 10:24 AM

I wouldn't be surprised either to see an improvement by advancing the timing a little bit. Much of this may be due to the fuel. The current lower cetane fuel available these days is not what these cars were meant to run on. You may well find that the ideal setting depends a lot on the fuel used.

barry123400 · #24 05-09-2006, 11:16 AM

On the last two posts I already agree other than I am starting to suspect the optimum position is a little advanced over the factory recommended one.

This I thought might be because of aging of certain components to some extent.
Or perhaps because of todays fuel.

Brian's thought is good as well or perhaps Mercedes engineering just decided on an arbitrary broad production value. But one thing is certain if you reflect upon it.

The manufactures that are using Milli volts as a production tool to set up new engines must have covered this area and went with it as a preferred method for some reason.

At first I also thought it should duplicate the factory setting but now even wonder if that is a good thought or not.
The answers probably are going to become evident as more and more cars are done.

First downside is my clutch did not appreciate the boost in power.
The equation so far is quick timing change versus four hours for me to replace clutch when I get to it. .
The clutch is not totally gone yet but is showing symptoms of not liking the additional power.
There is also some hang up or feeling that the original timing marks are written in stone.

At the time these engines were made the engineers had no way of allowing for aging or tolerance differences so they would have been forced to strike a timing position that was a compromise even for new engines mind what the majority of us drive.

Anyways glad to see you keeping an open mind.
It's pretty lonely here.
I am not seeing any evidence that the engine is advanced too far.
Not even the slightest trace.

Will try to do two more Volkswagens this evening and post back.

Brian if you decide to try it out make sure you add the two minor electronic parts to your meter.
The hunting meter would have driven me crazy if I was not already there.

Just pin punch so you can get back to your original marks as well.
Thats primarily for mental security and ease of finding your factory position.
Make the marks good as you will probably never be going back.

It will be a constant reminder also of why in He** you ever had the pump timed there in the first place whenever you notice the marks.

At this point I should post that I will not accept responsibility for doors blown off or transmissions parts littering the road.

Neither am I accountable for less frequent fuel stops.

Sorry, just gotta have a little fun.

Now seriously, what is the downside Brian.
You find out your present timing you fairly recently set is valid for your individual engine? Even if thats all thats accomplished it is an indicator itself of what bonehead is curious about to some extent.

Ever wonder why a spread of about 5 mpg is reported by various 123 and 126 owners?
Very few also describe power and acceleration correctly but we all realize some cars of the same type are quite a bit quicker than others.

As for the higher than average mileage figures most of us put the reports off to not doing a valid procedure to verify it properly or wishful thinking.
Some 240d owners quote 30+ while the majority of us think about 25 mpg for most examples of 240ds.
I am not referring to ebay ads either or the figure would be 40+.

Could that be the pumps are set at factory marks where the higher mileage ones had the pumps safely advanced by knowledgeable mechanics?
Is it not about time we found out?
The best way to help this site grow is to explore these things in a productive fashion.

Speaking for myself I have mastered the glow plug circuit I think and want to move on.

No that last statement is completely wrong!
I am still stuck there for awhile yet it appears.

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boneheaddoctor · #25 05-09-2006, 11:26 AM

well this will give us a basis of what actual degree of timing you end up with. Being that the RIV tool gives the most precise reading that is repeatible as well. we can reference it to a known accurate method of measuring actual timing. and see how far off it would end up and if there are wide swings between one vehicle or not. A good way to validate the results, and practicality of the millivolt method.

Brian Carlton · #26 05-09-2006, 11:29 AM

Barry, I presume that you used a digital meter and had trouble with the fluctuations of it. I've got a decent analog meter that can get down to very low voltages.........think I still need the capacitor for it? I'd be surprised if the meter can respond as quickly as the fluctuations.

coldwar · #27 05-09-2006, 12:23 PM

Quote:

Originally Posted by Brian Carlton

Barry, I presume that you used a digital meter and had trouble with the fluctuations of it. I've got a decent analog meter that can get down to very low voltages.........think I still need the capacitor for it? I'd be surprised if the meter can respond as quickly as the fluctuations.

Yep- from my days as a bench repair tech for the phone company, I always preferred an analogue meter for finding peak values- especially when close to the top of the peak. I think that preference is pretty universal among technicians.

BTW Barry- you're reporting doing a lot of VWs- For a Benz, how would you actually move the IP with the engine running?

Dave

barry123400 · #28 05-09-2006, 12:27 PM

Brian, for some reason the hunting is not fast really and the analogue meter might or might not follow it.

Hopefully the internal delays with the analogue meter will average it out but if not the capacitor and resistor are quick to add and not critical at all.
The input impedance of your analogue might also be a factor, we will see.
Needless to say make sure you do not expose that meter to glow plug activation voltage while in the Milli volt range.

I do not want to get too technical but the hunting should not be there in the first place in my opinion.
I only gave casual consideration of why it was occurring until the other gentleman mentioned he had it as well.
Have not given it much thought yet as it has no impact on what we are doing right now.

The hunting spread seems to remain over about .5 or .4 Milli volts.
Very consistent and moderately paced.
I had to always calculate the mean average while underway.
Right now I do not have the time to do a serious evaluation but am aware it is not just a spurious effect.
Something is really going on.

As bonehead suggests results are important.
I do respect his ability as well.
At present I feel we will never have an optimum timing number for these older engines.

It will seem we are going to be treating each one a little differently because of so many variables.
We should almost just think of it as custom timing.
My initial concern was that it would get into pre-detonation but surprisingly enough no evidence at all yet.

I hate doing assumptions but suspect the closer an engine is to new condition the less gain will be evident.
Even that may be wrong.
Could be the inverse.
It is still very early.
It may not have any value at all.
Intuitively I feel the potential is there though.

Something wild to finish this note with.
I thought the meter was getting inductive pulses for a moment and was counting them.
Was going to grab a scope and take a look at that harness.

Better to leave certain aspects to better minds and save my energy until someone reports something tangible that has to be dealt with as it is probably coming.
The next one is not likely going to be as easy to solve.

We as a group may never get by it either.
On the other hand it may not be lurking.
If we get past the preliminary stages of this procedure it might be interesting to investigate that apparent voltage instability further.
I really suspect it just reflects the difference between a hot glow plug and perhaps the plugs reaction while under the presence of the flame front.
But have no reason to buy that at this stage.
Any thoughts?.

.

barry123400 · #29 05-09-2006, 12:48 PM

Coldwar, for Volkswagen just loosening the mount bolts a little and tapping the pump with a wooden block and light hammer taps seems to do it.

I do not know how to describe the strength of tapping other than it depends on the leverage axis on the type of pump you are adjusting and you might feel better with a pry bar used reasonably...

I assume the worst probable senario is the pump would turn to the adjustment stop limits if the bolts were too loose and the hard line resistance was overcome by the engine.

I wish I had done a Mercedes pump so I could answer this better.
Guess after all is said and done you loosen the mount fastenings until you can budge by tapping or levering the pump.
Probably have to start and stop the engine a few times to find that situation.
You do not want to loosen more than required.
Yet you have to be able to move the pump a little with reasonable force.
You cannot make it loose enough to turn by hand in my opinion.

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barry123400 · #30 05-10-2006, 06:44 PM

Small item to report.

As the mileage builds have been watching for any additional heating effect.
Yes the engine is far more efficient but have decided since it burns a good 10% less fuel that is compensating for the period of hotter burn that is possibly of shorter duration.

Equaling a similar btu output perhaps.
I was concerned and thought if the injection was too early it would waste the heat by reflecting a warmer running engine.
I seem to be getting more fuel mileage than any I have ever had before and have had a pile of these.
Cannot pin it down yet for sure but the miles are building.
We did not do the two Volkswagens we were going to do today as other things arose.

Tomorrow might be a wash out as well.
Perhaps over the weekend may present a chance.
Will keep updating this thread as I still feel it is important.

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