Tuning with CIS - Page 24 - PeachParts Mercedes-Benz Forum

400Eric · #**346** 09-23-2011, 01:27 AM

Quote:

Originally Posted by RBYCC

Eric

Continue with trying out different FPR's as in the real world there exists production tolerance of any electro-mechanical component.

That's why when you build a race engine you "blue print" it, which is building to the exact spec without the production +/- manufacturing tolerance.
Manufacturing tolerances are the reason why two brand new identical cars may not have the same overall performance !!

If you listened to the claimed expert, then you would believe the 1-2 shift is 5300, which the expert after reading a bit more indicated that it should be 200 rpm below the rev limit set point.
I had posted a while back that my original 23 year old FPR still shifts at 6200 rpm !!!
If you believed that his claims were absolute, you may have stopped your trial and error process.
But you had common sense and basic logic which kept you going as you were already seeing results beyond what the factory specification maven believed possible !

You've proven yourself regardless of how the departed expert critcized you..

You're what getting greasy and going faster is all about.

Admirable

Ed A.

Thanks Ed for your post of support!

And yes, we definitely need more outside the box thinking in the MB hobby! I've been saying that for years!

I do need to clarify some other things a bit though......

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.

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

Ed,
This is Dave's first post regarding the FPRs. In the first sentence that I've highlighted he was actually coming to my defense and in support of my assertion that these FPRs are what dictates the first gear WOT shift points and against your original assertion that they don't. While I do disagree with the remaining highlighted sentences in Dave's post, and stated so in my first post after he made those statements, I hardly felt picked on or abused. While Dave and I do disagree from time to time, and I especially dislike his making fun of my efforts to make my M103s faster and quicker, implying as he does that it is a lost cause, I still always value his input, as I do yours. (And Jay's too!) I would hate to lose any of you!
Regards, Eric

400Eric · #**347** 09-23-2011, 05:53 AM

I've been playing with these FPRs on and off again for over 5 years now plus I just devoted my most recent track day solely to experimenting with them. My own observations and continuing questions are added to Ed's observations:

Quote:

Originally Posted by RBYCC

Yes the FPR cuts out the kickdown solenoid.
But understand the kickdown cycle is just for one down shift and upshift to the original gear.
Hence my "moot" comment.

Once the kickdown cycle is over neither the FPR or the kickdown solenoid has anything to do with subsequent gear upshift points, because the solenoid is no longer in the circuit and energized.

If it re-engaged as Dave stated through the FPR contact reclosing, the transmission would again downshift...

Subsequent shifts are controlled by the throttle position devices after the cycle is over.

I'm not so sure about this. I have one FPR that held second gear till the rev limiter kicked in at about 6,650 RPM! The funny thing was that it only held first till about 6,100 RPM!

What if I engage the first gear solenoid manually by placing the trans selector in it's lowest position at the starting line? That would mean that we got down into first because we did it manually through the solenoid instead of the FPR. Would that now allow the FPR to stay involved for one more upshift?

Quote:

Originally Posted by RBYCC

And yes the FPR has a breakaway speed or rev limit contact.
This speed as Eric has discovered is stamped on the FPR.

I've found it stamped on only about a third of the FPRs. If we eliminate the aftermarket ones, we still find that only about half of even the factory ones are marked with the RPM limit.

Quote:

Originally Posted by RBYCC

The conclusion is that the single upshift during the kickdown cycle occurs at 200rpm below the breakaway speed of the FPR.
Much different then the 5300 that Dave was adamant about until he found another Merc document that contradicted it.

So the higher the rpm stamped on the FPR, the higher the one and only kickdown upshift RPM will be...

Yes, but as I stated before, the production variances apparently vary wildly on these things because I've found that the stated RPM limits (and resulting 200 RPM lower shift points) on the FPRs can't be counted on. They just aren't always accurate. They are at least consistent though. Whatever RPM they shift at the first time I use them at WOT after plugging them in, is the same RPM that they shift at the tenth time I use them.
Regards, Eric

RBYCC · #**348** 09-23-2011, 08:46 AM

Eric

Quote:

This is Dave's first post regarding the FPRs. In the first sentence that I've highlighted he was actually coming to my defense and in support of my assertion that these FPRs are what dictates the first gear WOT shift points and against your original assertion

Dave stated " The WOT upshifts points are controlled by the signal present at the kickdown solenoid on the transmission "...perhaps semantics or misunderstanding on my part, but the FPR only controls the upshift in the "kickdown cycle"
You can achieve WOT without kicking down to a lower gear even with engaging the kickdown switch.
The energized kickdown solenoid doesn't matter at this point providing the bowden cable acts quicker then the kickdown solenoid and operates the TV for full upshift pressure.
You'll see what I mean in the below comment on first gear start.
Even a torque loaded start will not kick down a gear as there is no gear to kick down to.
If you run without an FPR ( providing you jumper and keep the pumps running ) the only thing you won't have is the ability to kick down.
The transmission will still upshift at WOT based on the TV and pressure to the valve body.
My logic is that FPR with a defect in Function-2 "RPM limitation after attaining engine max RPM" would never be noticed if the Kickdown cutout always opens at max rpm - 200rpm.

Quote:

What if I engage the first gear solenoid manually by placing the trans selector in it's lowest position at the starting line? That would mean that we got down into first because we did it manually through the solenoid instead of the FPR. Would that now allow the FPR to stay involved for one more upshift?

That is what I meant by stating that you can eventually engage the kickdown switch without the transmission kicking down...
If you are in first gear, then no matter how hard you mash the pedal there is no lower gear to kickdown to...the question is what controls the 1-2 upshift, the bowden cable and TV or the FPR kickdown cut out contact ? Either way the 1-2 should be at 6200 rpm +/-

I might be completely wrong and stand to be corrected but function -4 of the FPR is "kickdown cutout".
I understand this function as part of the "kickdown cycle" ( downshift-upshift one gear ) and not control of WOT non "kickdown cycle" shifts.
I stand by my post that this relay isn't that smart and even in the "kickdown cycle", I believe it receives it's coil initiation from the CIS -E TD speed signal.

Quote:

Yes, but as I stated before, the production variances apparently vary wildly on these things because I've found that the stated RPM limits (and resulting 200 RPM lower shift points) on the FPRs can't be counted on. They just aren't always accurate. They are at least consistent though. Whatever RPM they shift at the first time I use them at WOT after plugging them in, is the same RPM that they shift at the tenth time I use them.

Keep in mind that the specified settings tend toward more extreme tolerances as the relay ages..
Remember it's an electro-mechanical device that has coils, armatures, springs and contacts.
The only true comparison would be with new units.

There has been so much lengthy back and forth on the FPR function that I'm even confused...that's why I posted from the engine manual all that it actually does !!!

Let me try to be very simplistic.

"Kickdown" = the action of the transmission dropping to a lower gear when initiated by a device(s).
In the case of the M103 it's the kickdown switch completing the circuit to the kickdown solenoid.

The FPR , let's call it the "kickdown cutout contact" works in only one kickdown cycle which defined is down shifting from any higher gear to the next lower gear and upshifting back to the higher gear..
It opens as we finally agree at -200RPM below the rev limit set point.

Any upshift to the next gear ( after the kickdown cycle is complete ) is controlled by the transmission pressure control ( bowden ) cable.

The kickdown circuit will not rearm via the FPR until the kickdown switch again opens.
If the FPR contact reclosed after the kickdown cycle with the kickdown switch also closed it would once again shift to a lower gear.

Can we conclude that all FPR's are not created equal and that in proper operation, the higher the marked RPM, the higher the shift point on the kickdown upshift?

BACK TO THE SUBJECT OF EZL

Decided to dig deeper into all the EZL info that I have and from the " Service Manual M103 Engine" I'll quote:

"NOTE
In case of coolant temperature sensor interruption ( resistance = infinity ), the fixed characteristic of the Bosch ignition control units is no longer used and a certain ignition timing in the family of characteristics is selected, i.e. the ignition timing is advanced.

At full load the ignition timing is determined by the full load characteristic. Under consideration of the octane requirement the ignition is advanced at this stage ( higher engine torque ).

When a coolant temperature of approx 95C on these vehicles is exceeded, the ignition timing ( firing point ) is put back in the direction of "retard".

Let's assume that it not only applies to Bosch but the Siemens EZL's.

Jay is correct by changing the temp sensor resistance to bring in more timing.
The specified resistance at +20C is 2.28-2.72 KiloOhms
At +80C it's 290-364 Ohms.
Per the above removing the connection from the temp sensor to the EZL would give infinity ohms and bring in max advance ?
This is similar to how the EZL defaults with removal of the fixed R16/1 resistor which would input infinity ohms or open circuit.
Note that at idle or deceleration the temp sensor, vacuum, and R16/1 inputs are over ridden and the EZL operates on a fixed characteristic.

The other input that can be fiddled with is the Throttle valve switch.
Full open = Full advance.

All of the inputs end up in advance and:

"The power output stage triggered by the microcomputer controls the primary current of the ignition coil between terminals 16 and 31 ( 4-pole plug, supply ) "

This is a reason why I asked if you've tried a hotter coil...
I have a Nology coil that I will be installing along with Beru S1K solid silver electrode plugs once I get my car back....

Ed A.

400Eric · #**349** 09-23-2011, 11:27 AM

I would think that the EZL ECU (and the CIS-E ECU for that matter) would see the absence of the coolant temp sensor as a problem, a malfunction, a "fault" if you will, and as a result would go into a more conservative, less generous with the advance mode, a "safer" mode, a mode less prone to detonation since at that point the ECUs would have no idea how warm the engine is. In short, I think it would default to a more conservative mode to keep the engine out of detonation.

The removal of the R16/1 resistor is completely different matter though as that is an actual setting on a dial in some market's cars. It's not something the EZL would see as a malfunction.

I like Jay's mod as that definitely tells the ECU that everything is "Cool man, chill out". The thing that I fear about that mod though is that I think it only helps us when the engine is above 95C by helping the engine to continue to perform like it was when it was below 95C. In other words, it is preventing that nasty ignition retard from rearing it's ugly head at 95C. It prevents a loss of performance. That doesn't help me though when I'm trying to get more advance and more performance when the engine is at 80C. At that temp I can use more advance than I am getting now at that temp.

Regarding the throttle valve switch, we have to remember that we actually have less timing at WOT than we do under part throttle, so the "fiddling" might need to be in the other direction so to speak. (Telling the EZL that we aren't under WOT when we actually are. That might give us too much advance though.)

To that end, I have already been trying to keep the EZL in part throttle mode for a second longer while I dive into WOT mode by using a vacuum reservoir between it and the manifold but it hasn't seemed to have had any effect yet. More testing is needed and is under way. The signal from the throttle valve switch may be interfering with my efforts here though. It may be over riding the vacuum signal. Definitely uncharted territory here.

In all of my crazy experimenting I still haven't exceeded the detonation threshold yet! That confirms to me that these things are timed way too conservatively!

What about slotting the bolt holes of the crankshaft position sensor so we can make the EZL think that the crankshaft is a few degrees farther along in it's rotation, thus the need to hurry up and get those spark pugs fired?

Ed, I appreciate that you are really putting some thought into this. Please don't stop! Please continue! We still need a little more advance to get this thing out of the hole better!

What are your other ideas, Jay?

Come-on Dave, we need your thoughts too!

If I can't make these M103s any faster, I at least want to hear a little detonation so that I'll know I actually accomplished something!
Regards, Eric

RBYCC · #**350** 09-23-2011, 04:36 PM

Quote:

Originally Posted by 400Eric

I would think that the EZL ECU (and the CIS-E ECU for that matter) would see the absence of the coolant temp sensor as a problem, a malfunction, a "fault" if you will, and as a result would go into a more conservative, less generous with the advance mode, a "safer" mode, a mode less prone to detonation since at that point the ECUs would have no idea how warm the engine is. In short, I think it would default to a more conservative mode to keep the engine out of detonation.

Didn't make up what I posted, the statement was direct from the M103 Engine Manual. Look at the below jpg under "Note"

Removing or open circuitng the temp sensor creates infinite resistance, same as removing the R16/1 reference resistor.
Your comment of "Cool man, chill out" is exactly what the EZL does with infinite resistance input from the temp sensor. It thinks the engine temp is 20C or lower and advances timing to the max.
Remember the EZL has a very simple microprocessor in it and it's not very smart.
We are dealing with very rudimentary 30 year old electronics..
Hell in 1988 PC computers ran on 8086 processors that would take all day to boot up

Your temp sensor should have two one pole connectors, leave the one for the CIS-E on and remove the EZL plug to open circuit.

Quote:

The removal of the R16/1 resistor is completely different matter though as that is an actual setting on a dial in some market's cars. It's not something the EZL would see as a malfunction.

"Same-same" see above...open circuit on these two inputs make the EZL advance.

Quote:

I like Jay's mod as that definitely tells the ECU that everything is "Cool man, chill out". The thing that I fear about that mod though is that I think it only helps us when the engine is above 95C by helping the engine to continue to perform like it was when it was below 95C. In other words, it is preventing that nasty ignition retard from rearing it's ugly head at 95C. It prevents a loss of performance. That doesn't help me though when I'm trying to get more advance and more performance when the engine is at 80C. At that temp I can use more advance than I am getting now at that temp.

The EZL starts retarding ignition timing above 95C. The resistance in the temp sensor grows smaller as the engine coolant gets hotter.
Less resistance = less advance.

Open circuit to the EZL and it sees 20C.
EZL looks at 80C as normal, so 20C will advance timing as if it's trying to help the engine warm up.

Quote:

Regarding the throttle valve switch, we have to remember that we actually have less timing at WOT than we do under part throttle, so the "fiddling" might need to be in the other direction so to speak. (Telling the EZL that we aren't under WOT when we actually are. That might give us too much advance though.)
To that end, I have already been trying to keep the EZL in part throttle mode for a second longer while I dive into WOT mode by using a vacuum reservoir between it and the manifold but it hasn't seemed to have had any effect yet. More testing is needed and is under way. The signal from the throttle valve switch may be interfering with my efforts here though. It may be over riding the vacuum signal. Definitely uncharted territory here.

According to the M103 Engine Manual:
Idle speed position = 0 ohms
Full load position = 0 ohms
Part load position = infinite ohms ( open circuit )

Again applying the same logic as the R16/1 and temp sensor input, it may be that open circuiting of the Throttle valve switch may give full advance.

Not sure what over rides what but I would try to open circuit the three inputs discussed above to see if you gain any performance.

Quote:

In all of my crazy experimenting I still haven't exceeded the detonation threshold yet! That confirms to me that these things are timed way too conservatively!

What about slotting the bolt holes of the crankshaft position sensor so we can make the EZL think that the crankshaft is a few degrees farther along in it's rotation, thus the need to hurry up and get those spark pugs fired?

Interesting thought

Not sure if I would slot the holes as even a slight adjustment can result in an unaccurate output signal?
It looks like it picks up every 120 degrees on the ring gear and outputs an AC sine wave via a coax cable to the ECU.
The manual indicates a 680 ohm - 1200 ohm resistance in the pick up.
Check to see if your pickup is within spec by taking the coax connector off of the EZL ( ignition off ) and read resistance between center pin 7 and outer shield 31d which the manual indicates as 680 ohm - 1200 ohm.
The purpose is primarily for engine RPM and crankcase position.
This is one of the most critical inputs that can prevent the engine from running.

Quote:

Ed, I appreciate that you are really putting some thought into this. Please don't stop! Please continue! We still need a little more advance to get this thing out of the hole better!

What are your other ideas, Jay?

Come-on Dave, we need your thoughts too!

I'd welcome Dave as he has a great deal of knowledge..he just needs to adjust his negative attitude and realize that his comments are not always absolute !

Quote:

If I can't make these M103s any faster, I at least want to hear a little detonation so that I'll know I actually accomplished something!
Regards, Eric

Eric..you're running much faster then most !!

Just compare:

1988 300CE M103 Euro 16.0 / 89mph 1/4
1988 320CE AMG M103 15.4 / 91 mph 1/4

Call me crazy but I always felt my stock 1988 300CE M103 felt faster then my 1994 E320 M104 !!
Maybe it's the rear gear, but it seems to rev more freely !!

ED A.

More EZL stuff:

400Eric · #**351** 09-30-2011, 12:20 AM

Thanks for your informative post Ed. I'm still digesting the info and I'm still experimenting. A follow-up is coming.
Regards, Eric

400Eric · #**352** 10-21-2011, 05:36 AM

Still trying to figure stuff out.

We did finally get to test the 2.2 resistor though. We got THREE 16.2s out at our most recent track outing, despite the fact that it was pushing 90, and despite the fact that we were hauling more weight, including half of a tank more fuel than when we ran the 15.95, so we can at least say for sure that stepping up to the 2.2k resistor didn't hurt us! Still no detonation either!
Regards, Eric

400Eric · #**353** 10-21-2011, 06:10 AM

Don't forget, you have a higher compression ratio than I do.
Regards, Eric

400Eric · #**354** 10-21-2011, 08:55 AM

The old one did but not yours.
Regards, Eric

400Eric · #**355** 10-23-2011, 02:31 AM

Jay, you used to rev the pee out of your turbo M103. What was the RPM limit that you used to rev it to? I scored some more V8 fuel pump relays today and these ones only have a 5,500 RPM rev limit as opposed to the 6,000 RPM limit that the first V8 FPR that I scored has. If my math is correct, these 5,500 FPRs should translate to about 7,300 on a 6 cylinder which I'm sure is still way too high but I seem to remember that you used to routinely rev yours to 7,000 correct? I know that you retarded your cam to be able to make power at that high of a RPM level, what I am mostly trying to establish at this point is what RPM can these engines safely take? I want to know before I put one of these V8 FPRs in because I will likely be operating without a "safety net" because the rev limiter won't kick in till 7,300 RPM! This is why I've been referring to the V8 FPRs as the "nuclear option".
Regards, Eric

JayRash · #**356** 10-23-2011, 05:07 AM

Eric, the M103 has the fpr rev limit and has another in the ezl set at 7000. the ezl limiter is what u call a soft limiter. those engines can rev at 7k safely. just dont sit on the limiter. btw my M103 runs with no FPR, i replaced it witha basic bosch relay.

400Eric · #**357** 10-23-2011, 07:10 AM

OK, thanks Jay!
Regards, Eric

hijacker · #**358** 10-28-2011, 04:49 PM

Hi guys, I just went through the last few posts here. Advance is also controlled by the Air flow temperature sensor. I'd even say it should be the most that matters compared to EZL octane corrector, water temperature and air temperature. I am currently running with no resistor (position 1 of EZL-KAT octane corrector) and 100 octane fuel. Everywhere they document that the curves at idle are static no mater what EZL corrector resistor is there, but for my 190 E 1.8 1990 having the corrector to position 1 made my idle rpms to raise to 900/min. Cheers, -Nik

RBYCC · #**359** 10-28-2011, 11:17 PM

Quote:

Originally Posted by hijacker

Hi guys, I just went through the last few posts here. Advance is also controlled by the Air flow temperature sensor. I'd even say it should be the most that matters compared to EZL octane corrector, water temperature and air temperature. I am currently running with no resistor (position 1 of EZL-KAT octane corrector) and 100 octane fuel. Everywhere they document that the curves at idle are static no mater what EZL corrector resistor is there, but for my 190 E 1.8 1990 having the corrector to position 1 made my idle rpms to raise to 900/min. Cheers, -Nik

The early M103's ( mine is a 1988 ) don't have the temp sensor mounted in the intake air stream....

400Eric · #**360** 10-29-2011, 02:17 AM

M103s didn't get IAT sensors until 1990. My 88 and 89 don't have them either.

Gonna try the V8 FPR at the track tomorrow! Here's hoping we don't blow up our 236,000 mile engine!
Regards, Eric