Tuning with CIS - Page 23 - PeachParts Mercedes-Benz Forum

JayRash · #**331** 09-20-2011, 11:58 AM

The relay fpr cuts power to the kick down solenoid when a certain rpm range is reached thus box shifts. On same rpm every time

gsxr · #**332** 09-20-2011, 12:10 PM

Quote:

Originally Posted by RBYCC

So enlighten me are you saying that the kickdown solenoid is not energized at all times when the kickdown switch is engaged/closed ???

That is EXACTLY what I am saying, that you do not want to believe. The 1986 300E Intro manual as well as the ETM calls this out as a "kickdown cut-out control" based on engine RPM signal (regardless of the possible rpm typo - it's still a kickdown cutout at a pre-set RPM). I don't know how else to say it.

Quote:

Originally Posted by RBYCC

The kickdown switch has a normally open momentary contact which closes and remains closed as long as the pedal is depressed against it.
It will of course de-energize when the voltage supply is no longer present..but that's just common sense when you are analyzing a circuit made up of electro-mechanical components.

100% correct, and when the FPR cuts the voltage at a particular RPM, the solenoid de-energizes momentarily to allow the upshift. Otherwise it will hang in that gear at redline.

Quote:

Originally Posted by RBYCC

Let me repeat myself so you will better understand

Basic logic 101: Constant power + signal in range + kickdown switch =solenoid energized. Remove any element and the solenoid de-energizes.

See above.

Quote:

Originally Posted by RBYCC

I'm not looking at the schematic in the ETM, but we know your ETM was wrong about the 5300RPM upshift speed.

It's not my ETM. It's the factory W124 Mercedes Electrical Troubleshooting Manual with schematics.

Quote:

Originally Posted by RBYCC

Keep in mind that the only function of the kickdown solenoid is to do just what it's name states to immediately downshift to the next lowest gear when the accelerator pedal is depressed enough to activate the kickdown switch. After that it's moot in the scheme of upshifting to additional gears.

It is not moot. The solenoid must be de-energized briefly to allow an upshift. The trans will not upshift when the solenoid is energized. This is easy to test in a 400E/500E which have a "B" position on the shift gate (not present in most other W124 models) that bypasses the kickdown switch, and provides +12v at all times when "B" (S16/8) is engaged; as S16/8 has a constant +12v supply, which the kickdown switch (S16/6) does not. The trans will stay in 1st gear and bounce off the rev limiter, and not upshift. If what you claim is correct, this wouldn't be possible.

One minor correction to my previous post, on the 400E/500E, the voltage signal to S16/6 is interrupted by the BM module, not the LH module.

gsxr · #**333** 09-20-2011, 12:10 PM

Quote:

Originally Posted by JayRash

The relay fpr cuts power to the kick down solenoid when a certain rpm range is reached thus box shifts. On same rpm every time

That's what I've been saying. Thank you for confirming.

RBYCC · #**334** 09-21-2011, 08:03 AM

Dave

You're saying the exact same thing that I am but using different words...
You challenge and post a bit of my post without looking at the full context.
No more then semantics....

Yes, I stand by my statement that the kickdown solenoid has constant power to it with the kickdown switch closed until an "event" which is RPM related removes the source of power...

What you fail to understand is that an electrical circuit is described in normal operating conditions, anything that changes the "normal" condition is due to the logic of the circuit.
It's illogical and confusing to attempt to describe a circuit with each and every potential logic variable in place.

Read the schematic and follow with your finger the supply of power from the CIS-E to the FPR to the kickdown switch to the kickdown solenoid.
Normal operation the kickdown switch is not closed.
The "normal" circuit is complete to the one side of the switch and when the switch "event" closes it energizes the solenoid which remains energized until another "event' ( FPR RPM ) occurs to de-energize the solenoid

I've posted chapter and verse but you only want to read what makes you feel good !!!

Ed A.

Ed A.

oldsinner111 · #**335** 09-21-2011, 01:16 PM

Pardon again Gents:
As you know I have a resistor before my water temp sensor to alter timing and AFR.I do believe that AFR raised with timing causes complete burn,I still get the same mileage.

gsxr · #**336** 09-21-2011, 02:41 PM

When wrestling a pig in the mud, you both get filthy dirty... but the pig enjoys it.

Unsubscribing. Y'all have fun here.

JayRash · #**337** 09-21-2011, 04:50 PM

Hey dave don't quit I mean it man

400Eric · #**338** 09-22-2011, 01:07 AM

Yeah Dave we need your input as well as Ed's because we are still talking about other stuff here besides fuel pump relays.

Speaking of fuel pump relays, let's please don't lose sight of the simple fact that I have been and continue to successfully manipulate both of my M103's WOT shift points by simply changing fuel pump relays. Regardless of the hows and whys, these FPRs do make a difference in the WOT shift points!
Regards, Eric

RBYCC · #**339** 09-22-2011, 09:19 AM

Quote:

Originally Posted by gsxr

When wrestling a pig in the mud, you both get filthy dirty... but the pig enjoys it.

Unsubscribing. Y'all have fun here.

Dave

You really are one who always must be right, even if you're not...
The arrogance on your part on what you believe you know is a bit bizarre.
Big ego = insecurity.
You're not the Oracle on the Mercedes mountain..
Just another person as we all are..

Note how you deride Eric on what he's trying to do..
Yes, Eric doesn't go by the factory manuals that you need to believe in..
But Eric thinking out of the box is going faster then you ever believed..
It's this very thinking that was the "hot rod " performance movement in the 50's..

You want to insult, then go ahead...but what have you truly accomplished in your life other then cataloging volumes of Mercedes data??

So take your ball and go home....
We have our own "balls"....

Ed A.

RBYCC · #**340** 09-22-2011, 09:29 AM

Quote:

Originally Posted by 400Eric

Yeah Dave we need your input as well as Ed's because we are still talking about other stuff here besides fuel pump relays.

Speaking of fuel pump relays, let's please don't lose sight of the simple fact that I have been and continue to successfully manipulate both of my M103's WOT shift points by simply changing fuel pump relays. Regardless of the hows and whys, these FPRs do make a difference in the WOT shift points!
Regards, Eric

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.

JayRash · #**341** 09-22-2011, 11:46 AM

I think losing any member of the forum is never good. One way or another each member contributes to the general knowledge of the community either by fact or by food for thought and even disagreement.

Any way first gear on those cars works different to all other gears. Ie if u tighten the kickdown cable first shifts out early no matter what. And if u loosen it first holds more revs but the rest of the gears shift early. On b1 selectors it keeps kickdown switch constantly on but it also engages the old economy solenoid thing causing the box to think it has no kickdown cable. That's how first is locked then to rev limiter and won't shift out. Old w126 cars had b1 but had no economy switch solenoid thus they never reved to limiter in first.

JayRash · #**342** 09-22-2011, 12:04 PM

Quote:

Originally Posted by RBYCC

Dave

Correct me if I'm wrong but did I post "constant supply" ????

Please again refer to my post : "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."

The power is "constant" as it differs from a momentary initiating power/voltage to a device that electrical seals or mechanically latches.
The start position of the ignition switch is an example of "momentary" power that spins a starter and seals in relays and circuitry that keeps things operating.

Obviously you're not reading throughly as "87K" is a pin / terminal on the FPR ( N16/4 ). Voltage is constant and is not sent to the kickdown solenoid ( Y3 ) until the kickdown switch ( S30/1 ) closes.
This completes the circuit through the solenoid and to ground.

The FPR normally closed contact is between "87K" and and in series with a normally open contact originating at "87V".
This contact remains closed and supplies "constant" power ( originating at "87V" ) until it changes state, which is what "As long as this signal is within range" should be understood as !!

Basic logic 101: Constant power + signal in range + kickdown switch =solenoid energized. Remove any element and the solenoid de-energizes.
This also applies to another one of your queries !

The three coils in the FPR receive their initiating / energizing signals from the CIS-E control unit "speed signals" ( N3)
Nothing happens unless the engine confirms that it is running.
I would assume that the "processing" logic begins in the CIS-E control and is finalized in the OVP for the rev limit cutoff setting.

So enlighten me are you saying that the kickdown solenoid is not energized at all times when the kickdown switch is engaged/closed ???
The kickdown switch has a normally open momentary contact which closes and remains closed as long as the pedal is depressed against it.
It will of course de-energize when the voltage supply is no longer present..but that's just common sense when you are analyzing a circuit made up of electro-mechanical components.

Let me repeat myself so you will better understand

Basic logic 101: Constant power + signal in range + kickdown switch =solenoid energized. Remove any element and the solenoid de-energizes.

I'm not looking at the schematic in the ETM, but we know your ETM was wrong about the 5300RPM upshift speed..

I'm looking at the wiring diagram "Engine M103 Fig. 07.3.22 page 101 Model Year 1988 USA Models 107,124,126 and 201"

The kickdown solenoid does "bypass" the Bowden cable in the sense that it allows the hydraulic pressure to rise immediately, shifting the transmission to a lower gear and "overides' the mechanical Bowden cable for that moment that the switch initially closes.
Voltage moves much faster then a mechanical push/pull cable !!!

Keep in mind that the only function of the kickdown solenoid is to do just what it's name states to immediately downshift to the next lowest gear when the accelerator pedal is depressed enough to activate the kickdown switch.
After that it's moot in the scheme of upshifting to additional gears.

The Bowden ( real name is "Transmission Control Pressure Cable " ) cable is what sets the shift pressure and no matter what you do with the kickdown solenoid it won't change the max pressure setting.

You're also not mentioning another piece of the logic which is the full throttle stop setting which is required also to get max shift points.
Two mechanical inputs ( bowden and full throttle stop ) and one electrical input ( kickdown solenoid ) all must be adjusted and function to specification in order to get specified upshift point in WOT.

Ed A.

with regards to the kickdown solenoid being moot in upshift when all rest is in spec order i have to disagree, for when i manually engage my kickdown solenoid, it stops the box from shifitng up at the right rpm and even has the gear bouncing on the rev limitter for some time before it shifts. even my amg which has no fpr as per w124 m103, has a kickdown relay with depowers the solenoid after certain rpm range to allow proper upshift. i think it doesn't change the pressure inside as u said but it slows the pressure reaching that set point.

on my amg to be able to hold first i had to alter the shift pressure in the valve body, and now when i engage the solenoid it and keep it engaged it will never upshift what ever the gear is. first, second, or third. not the right way to do it since i have loosened my bowden cable to the max, meaning i have no proper kickdown, but i do use the selector any ways and i had no kickdown relay for the longest time so im used to it and i like it this way.

RBYCC · #**343** 09-22-2011, 02:31 PM

Quote:

Originally Posted by JayRash

with regards to the kickdown solenoid being moot in upshift when all rest is in spec order i have to disagree, for when i manually engage my kickdown solenoid, it stops the box from shifitng up at the right rpm and even has the gear bouncing on the rev limitter for some time before it shifts. even my amg which has no fpr as per w124 m103, has a kickdown relay with depowers the solenoid after certain rpm range to allow proper upshift. i think it doesn't change the pressure inside as u said but it slows the pressure reaching that set point.

on my amg to be able to hold first i had to alter the shift pressure in the valve body, and now when i engage the solenoid it and keep it engaged it will never upshift what ever the gear is. first, second, or third. not the right way to do it since i have loosened my bowden cable to the max, meaning i have no proper kickdown, but i do use the selector any ways and i had no kickdown relay for the longest time so im used to it and i like it this way.

Jay

My comment was "After that it's moot in the scheme of upshifting to additional gears."

Note I stated "additional gears"..
Understand that the kickdown solenoid by design when energized only kicks down one gear and then upshifts to the gear you were originally in...Beyond that the pressure setting of the transmission and the position of the bowden cable and full throttle stop take over.
The solenoid is in place to attain immediate action that drops the transmission down one gear.
It reacts instantly without the mechanical lag of the bowden cable.

The position of the bowden cable which is termed "transmission control pressure cable" does what it is named.
The transmission has an internal TV ( throttle valve ) which manages the hydraulic flow to the valve body...
Correct me if I'm wrong but isn't this what the bowden cable interfaces with and the solenoid over rides ?
The other component in the transmission is the vacuum modulator which impacts on the firmness of the shift.
You want a firm shift to prevent the clutches from slipping.

Is it possible to have full throttle without kickdown?
Sure is...

Go to the source, beyond the Merc manuals..the Bosch patent for the hydraulic kickdown:

"With these objects in view, the present invention provides an electronic control means responsive to a kickdown pedal operation to energize an electromagnet of an electrohydraulic transducer to operate a throttle valve to move to a position increasing the pressure of the pressure fluid control flow to the servo main valve, until a control flow flows at the highest pressure out of the throttle valve into a control valve and moves the control valve to a position permitting flow of pressure fluid through the outlet of the control valve to the transmission as a hydraulic kickdown signal actuating the transmission to shift down to the next lower speed stage. "

KICKDOWN ARRANGEMENT FOR A HYDRAULIC TRANSMISSION

Your modding of the valve body is no different then what I did over forty years ago to the 727A three speed Chrysler Torqueflite behind 7 liter+ max performance Hemi and Wedge engines.
Never had a rev limiter on an engine that would spin to 8500rpm.
In essence you have converted the transmission to a full manual operation.
The old cars American used kickdown linkage instead of a bowden cable and with full manual operation this linkage as the bowden cable is no longer needed.
You've manually over ridden the throttle position pressure control and have no need for a throttle position sensitive device to control the shift point.
You really don't need all the features of the Merc FPR as most are there for safety.

Ed

RBYCC · #**344** 09-22-2011, 02:53 PM

Quote:

Originally Posted by JayRash

I think losing any member of the forum is never good. One way or another each member contributes to the general knowledge of the community either by fact or by food for thought and even disagreement.

Jay

No one asked Dave to leave..
He did it on his own volition.
Have you noticed on this and other forums that when Dave is intellectually challenged he tends to end up getting aggressive and oft times name calls ?
No different on this forum with my discussion on different types of Dynos...
He just can't admit he is wrong or is not familiar with something and because of his own insecurities, it's easier for him to leave then accept that there are others, you and Eric included, that may not know the Merc manuals inside and out, but have accomplished a great deal and gained hands on knowledge.

"Once we believe we have no more to learn, it's an admission that we haven't learned enough !!!"

It's his loss not ours if he can't handle a logical, factual challenge to his "knowledge"...

Quote:

Any way first gear on those cars works different to all other gears. Ie if u tighten the kickdown cable first shifts out early no matter what. And if u loosen it first holds more revs but the rest of the gears shift early. On b1 selectors it keeps kickdown switch constantly on but it also engages the old economy solenoid thing causing the box to think it has no kickdown cable. That's how first is locked then to rev limiter and won't shift out. Old w126 cars had b1 but had no economy switch solenoid thus they never reved to limiter in first.

It's still the TV in the transmission that ultimately controls the hydraulic pressure and shifting in the transmission.

All the external devices modify the action of the TV.

You can go with full manual as you did which is optimum for performance as long as you know when to shift and how much RPM over after the shift you will have, so you don't over rev.

Keeping all the settings to stock spec will give optimum performance as designed in a fully automatic 722.3/4

Ed A.

RBYCC · #**345** 09-22-2011, 04:10 PM

Let me stand by my original post that the FPR isn't that smart..
This is what caused Dave to get his feathers ruffled and leave..

ONCE AND FOR ALL, LET'S PUT THE FUNCTIONS OF THE FPR TO REST

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.

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

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...

Heer's the documentation from "Service Manual Engine M103 Publication S-2421-103.

Maybe Dave will come back and play with us because Merc has documentation which he failed to discover that supports my lengthy posts...