Tuning with CIS - Page 21 - PeachParts Mercedes-Benz Forum

400Eric · #**301** 09-16-2011, 11:34 AM

Been studying that page and cross referencing with some other material that I have.

Those EZLs that offer 2 degrees less advance under no vacuum conditions (high load conditions) are for the 2.6 M103 (M103.940). It makes sense when you think about it. With about a 1/4 inch smaller bore, the 2.6 doesn't need as much ignition advance!

Ed, thanks again big time for the info and link!
Regards, Eric

RBYCC · #**302** 09-16-2011, 12:24 PM

Quote:

Originally Posted by 400Eric

Been studying that page and cross referencing with some other material that I have.

Those EZL that offer 2 degrees less advance under no vacuum conditions (high load conditions) are for the 2.6 M103 (M103.940). It makes sense when you think about it. With about a 1/4 inch smaller bore, the 2.6 doesn't need as much ignition advance!

Ed, thanks again big time for the info and link!
Regards, Eric

Eric

I'm researching a bit more on the potential EZL differences.
Go to page RA15 ( fourth page ) of the below link...
Seems like there were ignition map changes made to cure some problems with manual transmission cars..

http://www.tglmarketinginc.com/mbforum/servman/MB%20Service%20Manuals/www.pauldrayton.com/uploadfiles/merc/Service/W124/w124CD1/Program/Engine/103/Tech_Mods/comb3.pdf

Ed

RBYCC · #**303** 09-16-2011, 12:30 PM

Quote:

Originally Posted by 400Eric

Been studying that page and cross referencing with some other material that I have.

Those EZL that offer 2 degrees less advance under no vacuum conditions (high load conditions) are for the 2.6 M103 (M103.940). It makes sense when you think about it. With about a 1/4 inch smaller bore, the 2.6 doesn't need as much ignition advance!

Ed, thanks again big time for the info and link!
Regards, Eric

Eric

I'm researching a bit more on the potential EZL differences.
Go to page RA15 ( fourth page ) of the below link...
Seems like there were ignition map changes made to cure some problems with manual transmission cars..

http://www.tglmarketinginc.com/mbforum/servman/MB%20Service%20Manuals/www.pauldrayton.com/uploadfiles/merc/Service/W124/w124CD1/Program/Engine/103/Tech_Mods/comb3.pdf

Also a bit more info from another website:

"Yesterday I ran some tests to characterize the spark advance - engine revs curve with a dial back timing light using the OE US model 750 ohm resistor and zero (shorted the plug) and infinite (removed the resistor) resistance.

The shorted plug case is supposed to represent the least rate of advance and least total advance, and the open circuit case the highest advance rate and most total advance.

For all cases the initial timing was 9 and the vacuum line to the EZL module was removed and plugged, but prior tests indicated maximum vacuum advance of 14 degrees.

Figure reading error is plus/minus one degree and 100 revs, but might be a little more at high revs since the mark tended to jump around a little more.

750 ohm OE resistor:
17@1500
21@2000
27@2500 (maximum)
27@3000
27@3500

Zero ohm - plug shorted
09@1500
13@2000
18@2500
19@3500
21@4000 (maximum)

Infinite ohm - open circuit
16@1500
21@2000
27@2500
28@3500 (maximum) "

400Eric · #**304** 09-17-2011, 03:16 AM

What year/model/engine/trans/emissions market (49 state or Calif?) was the subject car? Could you please link us to that one? Sounds like an interesting read! Most everybody has either said it made things better or made them worse, I think this is a first where a guy showed it did nothing! Kinda funny! But I don't doubt it either! I really need to find my old Sears Craftsman dial back timing light (I haven't seen it for over 2 years) and do what he did on my cars!

This may be a case like what you said where the total advance number didn't change much but "the area under the curve" was pumped up a bit under part throttle conditions without the plug. I think the only way to find out that one would be to hook a hand held vacuum pump up to the EZL and try the test with and without the plug with the pump set at 5 inch vacuum increments (5, 10, 15) and see if there are any differences in the amount of advance between the plug in and plug out.

But there is another potential issue that muddies everything up. It could also very well be that all some of these resistor settings do is simply change the temperature point that the EZL goes to a different advance map. I'm pretty sure we were taking about this earlier in this thread. I think we've seen some strong evidence that all changing the resistor value in US cars does is postpone the point where the high engine temp ignition retard kicks in. This would also explain why Jay's resistor mod didn't help Benzer1 like it did Benzer3. Because Benzer1, unlike Benzer3, is already benefiting from a non-cat EZL setting (with it's resistor removed) and that causes the retard point to be high enough that I would need for the car to be pretty hot before Jay's mod started to be of a benefit. This would also explain why I'm now getting away with a 2.2k ohm resistor now, which I shouldn't be able to get away with. (Again, we need to remember that I was getting Benzer3 pretty hot when I was testing Jay's mod at the track in that car.) To put Benzer3 into this same non-cat EZL mode requires a change from a number "2" EZL pill to a number "6" EZL pill which is something I didn't try until much later than the times I tried Jay's mod on that car at the track. Plus, Jay's mod also helped that car get more fuel too, which it did need at that time, because I hadn't found a WOT fuel enrichment ECU yet, like what I'm running now. So I still to this day don't know just exactly how much of the performance gain seen at the track with that mod was form timing increase and how much was from fuel enrichment. I do remain convinced to this day though that it was a little of both. (For the benefit of those late to this thread, this stuff was talked about earlier in this thread but it was over 2 years ago and bears repeating.) The long and the sort of all of this is that this might explain why, for some folks, a performance gain is noted and for others it isn't. It may all simply depend on what the temperature of the engine is whether you see a gain or not. It also appears that, starting with the KE5 systems that came out in 1990 MY, the ECUs had the ability to figure out when they were being fed bogus information and they also had/have the ability to disregard said bogus information. That's yet another variable.

The biggest mystery of all is why the people who know the answers to these question remain determined to take this knowledge with them to the grave rather than sharing it and passing it on!

I still maintain though that as relatively simple as these CIS-E systems are, especially the pre-90 KE3 ones, we outta be able to figure out how to outsmart them!

As for that other link, yeah that is interesting, now if we could just find out what exactly the changes were and the actual part numbers of the EZLs! Probably kind of a dead end though as manual trans W124s are super rare in the US. I've read that only about 300 were sold here. Is that true?

And how about that change made in 2/86 raising the governed speed up to 7,000??? Sounds sweet! That's M104 territory but the M104 wasn't out yet! Maybe that is for the 16 valve 4 but the note only mentions "camshaft" not "camshafts".
Regards, Eric

RBYCC · #**305** 09-17-2011, 08:29 AM

Quote:

Originally Posted by 400Eric

And how about that change made in 2/86 raising the governed speed up to 7,000??? Sounds sweet! That's M104 territory but the M104 wasn't out yet! Maybe that is for the 16 valve 4 but the note only mentions "camshaft" not "camshafts".
Regards, Eric

The answer may lie in the model year ""Introduction to Service" book.
This book is produced yearly and shows the changes from the previous model year along with tech specs and troubleshooting/testing parameters.

I have the one for MY 1988 which has many pages on the CIS-E, most addressing the California versions and only one paragraph for the EZL:

"EZL Electronic Ignition System

Engine M103

New ignition control module with modified ignition output curve during transition to idle speed.

Test and adjustment values remained unchanged "

This tells me that although the test values that we all know are the same, the actual ignition curve may vary from year to year and country to country !!
My guess is that the earlier M103 EZL's have a more aggressive curve then later models with California versions being the least desirable performance wise.

Ed A.

400Eric · #**306** 09-17-2011, 05:06 PM

Which is exactly why I want to try different ones at the track!! I also am going to try different CIS-E ECUs at the track too!! That's why I am adapting several to my 89 as we speak!! The problem for me is that the only thing that I find at my local U-Pull-Its are California market cars cause I'm in California! I did find that one very early 49 state W124 and I did get it's CIS-E ECU but didn't get it's EZL. (I can't remember why it worked out that way.) That early 49 state ECU is by far my quickest ECU at the track so far but we are gonna do more extensive testing at the track the next time we go.

I'm even also trying different fuel pump relays because they are what control the trans upshift point. That is what I did last time at the track. For some reason, the production tolerances on those things is deplorable!! They vary wildly!! The one that came in my 88 (which I think is the original because it was produced in early 88) has a 1st to 2nd upshift point at WOT of only 5,000 RPM!! That's way too low even for a close ratio trans equipped W124! Yet it's 2nd to 3rd shift point is great (about 6,200). With the wide ratio trans that debuted at the beginning of the 89 MY, there is a very big spread between first and second, which makes it even more important to wind the pee out of it in first so that you are not too far below the torque peak when you hit second. These relays are sometimes marked on top what their RPM limit is but that has turned out to be fairly meaningless. Case in point: most of them that are marked say 6,350 but the one that I have that says 6,550 is the one that shifts at 5,000 RPM! I have only one other one that says 6,550 but it doesn't even work! It is in fact the only one I have that doesn't work! (I have accumulated about 15. I carry them in their own little designated tool box!) I'm also gonna try Jonathon's idea and try a M117 relay as soon as I can remember to get one. (I've been to the junkyards about 10 times since he suggested that but I keep forgetting to get some.)

All of this 2 bit penny pinching silliness adds up! It has added up to a uncorrected 15.95 for us on a fairly warm day with an essentially stock 3.0 300E with over 235,000 miles on it!

I have yet to see a quicker time posted on the internet or in a magazine for a stock or essentially stock US market M103 300E.

(C&D got a CORRECTED 16.3 out of a 86). Even some more heavily modded ones aren't getting that! Even ones whose owners have installed lower gears!

(Check DragTimes!) That 15.95 corrects to a 15.5 which is equal to the corrected E/Ts that the magazines got from M104s! I just wish that 15.95 was repeatable.

(I've gotten a grand total of three 15s from Benzer1.)
Regards, Eric

400Eric · #**307** 09-17-2011, 08:29 PM

Ed,
I just noticed something interesting on one of those pages you linked: Our # 006 545 76 32 EZL is listed as an "alternate" for the manual trans cars on the modification dated 03/87!
Regards, Eric

RBYCC · #**308** 09-18-2011, 09:37 AM

Quote:

Originally Posted by 400Eric

I'm even also trying different fuel pump relays because they are what control the trans upshift point. That is what I did last time at the track. For some reason, the production tolerances on those things is deplorable!! They vary wildly!! The one that came in my 88 (which I think is the original because it was produced in early 88) has a 1st to 2nd upshift point at WOT of only 5,000 RPM!! That's way too low even for a close ratio trans equipped W124! Yet it's 2nd to 3rd shift point is great (about 6,200). With the wide ratio trans that debuted at the beginning of the 89 MY, there is a very big spread between first and second, which makes it even more important to wind the pee out of it in first so that you are not too far below the torque peak when you hit second. These relays are sometimes marked on top what their RPM limit is but that has turned out to be fairly meaningless. Case in point: most of them that are marked say 6,350 but the one that I have that says 6,550 is the one that shifts at 5,000 RPM! I have only one other one that says 6,550 but it doesn't even work! It is in fact the only one I have that doesn't work! (I have accumulated about 15. I carry them in their own little designated tool box!) I'm also gonna try Jonathon's idea and try a M117 relay as soon as I can remember to get one. (I've been to the junkyards about 10 times since he suggested that but I keep forgetting to get some.)

Regards, Eric

Eric

Save your money and time....
The fuel pump relay isn't that smart and does not control the transmission upshift points.
It has a single setting that receives a speed signal ( same as the tach signal ) and opens a contact that cuts out the fuel pump at the preset RPM.
In essence it stops the fuel supply and functions as a rev limiter.

The shift point is dictated by position and rate of change of the accelerator pedal. ( Also at times brings into play the kickdown switch and solenoid )

The transmission shift points are controlled by pressure and the transmission pressure control cable ( bowden ) is the device that is adjusted to change the upshift points.
If adjusted correctly you should upshift at 6200+ RPM under WOT conditions.
That is why the majority of the FPR's are marked 6350 RPM to prevent over revving.

The firmness of the shift is controlled by the modulator.

Ed A.

P.S.

Do you still run the standard stock ignition coil ?

gsxr · #**309** 09-18-2011, 11:58 AM

The WOT upshifts points are controlled by the signal present at the kickdown solenoid on the transmission. The voltage to the solenoid is interrupted by something upstream, which varies on different engines/models. On the 400E/500E, it is the LH module which controls the WOT upshift RPM. On the 300D, it's the KLIMA relay. On the W126/M117, it's the fuel pressure relay. According to the FSM (ETM, printed page 113, PDF page 23 of 275)... Eric is correct, it's the FPR (N16/4) on the 1986-89 300E which controls the WOT upshift. Note that for 90-up gas models (except V8), it's not the FPR, but the main engine computer (N16).

Eric, what you describe sounds more like a transmission issue, but I've seen this before on other models where the 1-2 upshift is below normal RPM (even with a properly functioning kickdown). It would be difficult to diagnose fully without connecting a test light to the solenoid wire that you could observe while driving at WOT, to determine if/when the kickdown signal turns off (no voltage). I would not expect swapping FPR's to fix your problem.

The Bowden cable primarily controls only part-throttle shifts, although it must be connected to have proper shifting through the gears. The kickdown solenoid must be functioning required to get "redline" shifts. On my E500, with the kickdown solenoid unplugged, the 1-2 upshift occurs around 4500 or so, but the 2-3 is still at 6000. I'm not sure how the 300E tranny is programmed, but you may want to investigate this more closely, Eric. The Bowden cable will still provide kickdown downshifts even if the solenoid (or wiring) is dead, fooling you into thinking the solenoid circuit is working, when it ain't.

Thinking about it more (as I type)... I'd almost guarantee your Benzer kickdown circuit is not functioning. First check is to measure the resistance of the solenoid, a good one is ~12 ohms, bad one will be much higher (say, 100 ohms, or more). Next up is to measure voltage at the wire at the solenoid on the tranny with the key on and kickdown switch engaged (press pedal to floor), you should see +12v when the switch is clicked.

BTW - the RPM markings on the FPR are the engine rev limit, NOT anything to do with transmission shift RPM's.

duxthe1 · #**310** 09-18-2011, 12:30 PM

The 1-2 upshift has an adjustment on the front of the valve body. It is a small allen 2-2.5mm that sets pressure on a spring that governs that upshift. I was just in there last week servicing the trans and lowering that shift point in mine.

Unrelated, I also checked for the updated 3 and 4 accumulators which it had, guess I'm living with the soft 2-3 upshift. The good news is that the fluid was still good and the recent whine was caused by a failing filter.

gsxr · #**311** 09-18-2011, 12:39 PM

Quote:

Originally Posted by duxthe1

The 1-2 upshift has an adjustment on the front of the valve body. It is a small allen 2-2.5mm that sets pressure on a spring that governs that upshift.

Yep, the TSB is here:

http://www.w124performance.com/docs/mb/transmission/trans_WOT_upshift_RPM.pdf

Note that it specifies 2-3 upshift, not 1-2 upshift.

RBYCC · #**312** 09-19-2011, 08:21 AM

Quote:

Originally Posted by gsxr

The WOT upshifts points are controlled by the signal present at the kickdown solenoid on the transmission. The voltage to the solenoid is interrupted by something upstream, which varies on different engines/models. On the 400E/500E, it is the LH module which controls the WOT upshift RPM. On the 300D, it's the KLIMA relay. On the W126/M117, it's the fuel pressure relay. According to the FSM (ETM, printed page 113, PDF page 23 of 275)... Eric is correct, it's the FPR (N16/4) on the 1986-89 300E which controls the WOT upshift. Note that for 90-up gas models (except V8), it's not the FPR, but the main engine computer (N16).
BTW - the RPM markings on the FPR are the engine rev limit, NOT anything to do with transmission shift RPM's.

Dave

Correct me if I'm wrong...perhaps a difference in our semantics

The Fuel Pump Relay N16/4 always has power at terminal 87K ( pin 6 ) as long as a speed signal, TD is received and it is less then the high rpm limit set point of the specific relay ( Hence the different relay RPM ratings that Eric cites ).

As long as this signal is within range, 87K sends constant power to the Kickdown solenoid Y3 which will not energize until the Kick down switch S30/1 closes and completes the circuit to ground.
At the same time the " in range " TD signal allows the FPR to provide constant power through 87 (pin 7 ) to the fuel pumps.

The only normal " upstream " events that can interupt the constant power to the kickdown solenoid and the fuel pumps is loss of speed signal TD or RPM above the preset limit of the Fuel Pressure Relay N16/4.
Either of these "events" shuts the engine down by removing fuel supply.

A defective FPR which keeps power ( contact remains closed ) on the Kickdown solenoid will cause the trans to shift higher then specified or if if the defect keeps power off ( contact remains open ) then it will prevent upshifts.

I stand by my comment that the FPR only has the ability to interupt the upshift when it sees an RPM point above the rev limit and does not alter the point at which the transmission upshifts in normal driving or WOT.
It is equal/less important then the kickdown switch which is the only device that has the ability to complete the WOT circuit.
It only provides power that allows the transmission hydraulic pressure to shift the transmission at preset and adjustable pressure levels.

In essence it's not a "logic" control device that thinks and makes decisions to change transmission shift point parameters but merely a switch that tells the transmission that the engine is running and that it is not running beyond it's limit.
From that point on the transmission pressure settings dictate the RPM shift point under WOT where as in normal driving the pressure setting is controlled by the transmission pressure control cable ( bowden )

400Eric · #**313** 09-19-2011, 08:24 AM

Quote:

Originally Posted by RBYCC

Eric

P.S.

Do you still run the standard stock ignition coil ?

Yes. I thought the stock MB coils are just fine?

Quote:

Originally Posted by gsxr

The WOT upshifts points are controlled by the signal present at the kickdown solenoid on the transmission. The voltage to the solenoid is interrupted by something upstream, which varies on different engines/models. On the 400E/500E, it is the LH module which controls the WOT upshift RPM. On the 300D, it's the KLIMA relay. On the W126/M117, it's the fuel pressure relay. According to the FSM (ETM, printed page 113, PDF page 23 of 275)... Eric is correct, it's the FPR (N16/4) on the 1986-89 300E which controls the WOT upshift. Note that for 90-up gas models (except V8), it's not the FPR, but the main engine computer (N16).

Eric, what you describe sounds more like a transmission issue, but I've seen this before on other models where the 1-2 upshift is below normal RPM (even with a properly functioning kickdown). It would be difficult to diagnose fully without connecting a test light to the solenoid wire that you could observe while driving at WOT, to determine if/when the kickdown signal turns off (no voltage). I would not expect swapping FPR's to fix your problem.

The Bowden cable primarily controls only part-throttle shifts, although it must be connected to have proper shifting through the gears. The kickdown solenoid must be functioning required to get "redline" shifts. On my E500, with the kickdown solenoid unplugged, the 1-2 upshift occurs around 4500 or so, but the 2-3 is still at 6000. I'm not sure how the 300E tranny is programmed, but you may want to investigate this more closely, Eric. The Bowden cable will still provide kickdown downshifts even if the solenoid (or wiring) is dead, fooling you into thinking the solenoid circuit is working, when it ain't.

Thinking about it more (as I type)... I'd almost guarantee your Benzer kickdown circuit is not functioning. First check is to measure the resistance of the solenoid, a good one is ~12 ohms, bad one will be much higher (say, 100 ohms, or more). Next up is to measure voltage at the wire at the solenoid on the tranny with the key on and kickdown switch engaged (press pedal to floor), you should see +12v when the switch is clicked.

Dave, Dave , Dave, I appreciate your thoughts, help, efforts and insight but in this case it really is simply as I stated: These FPRs vary wildly. I only know this because I started experimenting with them when I was trying to figure out why Benzer2 had such a crazy low (5,000 RPM) 1st to 2nd WOT shift point. Benzer1 on the other hand, had a perfect 6,400 RPM WOT 1st to 2nd shift point. I simply switched the FPRs between the 2 cars and Benzer1 became Benzer2 while Benzer2 became Benzer1! It was nuts! That's when I started collecting FPRs from the JYs and trying them. For a while, the one that came with Benzer1 remained the champ. When I finally found a FPR that was almost as good as B1's FPR, I threw it in B2 and I stopped experimenting with the FPRs and pursued other things. Benzer2 has the older, close ratio trans so it's not as critical to wind the pee out of him in first anyways since the ratio spread between first and second gears isn't as large.

Later, when I did the "T bar" mod to B1, his WOT shifts quickened up so much that they were now actually occurring earlier! So much so that we were below our torque peak when we hit the next gear. (Shifts that had been occurring at 6,400 were now occurring at 6,000!) So I began the search again in earnest to find a FPR that had as late a shift point as I could find. I have one in there now that is shifting at 6,300 which I'm pleased with considering how the quicker shifts made the shifts occur earlier. I also have a FPR that does them at 6,200 as a back-up if the other one burns out. BTW, I thought that FPR stood for Fuel Pump Relay, not fuel pressure relay.

I know all of this sounds pretty nuts to anyone who hasn't actually experimented with these FPRs themselves. (Which is probably everyone reading this thread.

) You guys are welcome to experiment for yourself! I've found that the aftermarket ones made in Hungary are the most generous with the "Rs". That crazy 5 grander FPR is a factory MB one BTW, and judging by the date printed on it I am confident that it is in fact B2's original FPR. It works great in every other way, and it's other WOT shifts happen at about 6,100-6,200, it's just that critical 1-2 shift that is off. (Way off!)

Every other function, upshifts, downshifts, etc, operate as they should on both B1 and B2. These cars are really a delight to drive now! In many ways they are more fun than my 2 V8 cars! (But only after I modded them! Knocking a full second off of their 1/4 mile E.Ts worked wonders!) I've pumped up their low-end torque so much that even their 2nd gear starts aren't annoying anymore! I used to always end up too deep in their throttles, which forced a downshift into first, because they always moved too slow starting in second, but not anymore!

Again, there is nothing wrong with B1 or B2. It's just crazy me looking for a few more tenths in the 1/4 mile! Just looking for that low hanging fruit!

Quote:

Originally Posted by gsxr

BTW - the RPM markings on the FPR are the engine rev limit, NOT anything to do with transmission shift RPM's.

I know that but I was still thinking and hoping that the FPRs that have the higher rev limit might also have a higher shift point.

Quote:

Originally Posted by RBYCC

A defective FPR which keeps power ( contact remains closed ) on the Kickdown solenoid will cause the trans to shift higher then specified or if if the defect keeps power off ( contact remains open ) then it will prevent upshifts.

Ed, I keep re-reading your most recent post trying to grasp it. Are you saying that when these FPRs aren't functioning properly the result will be the shift point will be too high? How would this explain Benzer2's original FPR's 5,000 RPM 1-2 WOT shift point? Not trying to be argumentative, just trying to grasp what you are saying.
Regards, Eric

400Eric · #**314** 09-19-2011, 10:49 AM

Some of these FPRs have a "87H" pin and some don't. What is that for? What does it do? It doesn't seem to affect the interchangeability on my cars it being there or not.
Regards, Eric

RBYCC · #**315** 09-19-2011, 12:44 PM

Quote:

Originally Posted by 400Eric

Ed, I keep re-reading your most recent post trying to grasp it. Are you saying that when these FPRs aren't functioning properly the result will be the shift point will be too high? How would this explain Benzer2's original FPR's 5,000 RPM 1-2 WOT shift point? Not trying to be argumentative, just trying to grasp what you are saying.
Regards, Eric

Eric..

Not taken as argumentative just asking questions as I most times do for better understanding !!!

If the relay contact that supplies power to the Kickdown solenoid sticks closed or opens later then the rev limit then the transmission will shift at a higher then specified RPM.

Conversely if it bounces or opens prematurely the shift point will be lower then specified.

The 5000RPM 1-2 shift point may be caused by a faulty FPR, kickdown switch or kickdown solenoid...

Always best to start with the switch that is behind the gas pedal as this switch completes the circuit to ground and energizes the solenoid...

Quote:

Some of these FPRs have a "87H" pin and some don't. What is that for? What does it do? It doesn't seem to affect the interchangeability on my cars it being there or not.
Regards, Eric

I'm looking at the 1988 wiring diagrams that cover all automatic Federal and California N16/4 relays for the W107, W124, W126 and W201 and they all show as 9 used pin relays with designations of 87V, 30, 87, 31, TD, 50, TF, 87K, 15.

The manual shift cars with the N16/3 FPR have eight usable pins which is less the 87K pin for the kickdown switch/solenoid.

The 87H if I recall is for cars that require a heated O2 sensor.

Back to the CIS and trying to change the ignition map...
Doubtful the map can be changed, just tricked by changing input values of temp sensor as discussed...
What drives the EZL map..RPM ?
If so can you trick the EZL to see a slightly higher RPM then actual RPM bringing in the advance faster ?