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W124 400E, W126 500SE
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Discussion Starter #1
I'm not sure if it's called TPS, but it's the electrical part mounted on the other side of the injection body than the EHA. It has 3(?) wires going to it. It has a potenciometer inside and (you guess it) mine is busted ;-)

does anybody know the P/N? It's a 1986 500SE (EURO, 180kW)

Thanks
 

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2012 CL550 4MATIC Coupe
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Post a pic up and pm me your VIN pls.
 

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W124 400E, W126 500SE
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Discussion Starter #3
This is the same part on a different fuel distributor, I can take a photo of mine in the evening... The part in question is the one in the black circle. It should be a TPS.

PM with VIN sent... thanks!
 

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2012 CL550 4MATIC Coupe
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I'm sorry, can you get a better pic of it pls?

I don't have, nor ever had, a 6 cyl. I do have that FD sitting right here, but not the AFM. Maybe ask Kodiakj2 or Jon White or Jono. Those guys really know a lot more than I do and probably will know right what it is.
 

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'82 Euro 500SEL, '85 Euro 500SEC AMG WB Cabriolet,'86 Euro 500SEC RUF
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It is the electrical plug on the side of the FD. eha on the driver's side (LHD0 and this connector is on the passenger side. Your car has it also Mclare, Rose has it too, but I do not know the name of it.
 

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1986/1990 W126
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Is it definitely busted? Apparently those dont break too often. They are a slight pain to replace - cheap to buy but the intake needs to come off.
 

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Discussion Starter #7
Sorry, I didn't get to making a picture :( hopefuly tomorrow.

Yeah, there are two electrical parts on the fuel distributor - on the driver's side is EHA, and on the other side there's this "TPS" - it reports the throttle plate position back by increasing resistance (i think).

In my case, it has "holes" at certain sports, that are worn out from use (it has a brush inside) - I don't think it can be repaired easily. My old 420SE had this as well near the idle resting position.

I'm not sure but I think I found it:

http://mb.ilcats.ru/part/class/1/ccode/1/cat/322/type/117/subtype/965/group/07/subgr/013/retcat/64Z/rettype/126/retsubtype/036/vin/WDB1260361A248164

part number 158 in the picture. I'll take a look tomorrow, now I'm not sure on which part (upper/lower) it is actually mounted...
 

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Discussion Starter #8
Is it definitely busted? Apparently those dont break too often. They are a slight pain to replace - cheap to buy but the intake needs to come off.
hmmm, I had it removed on my 420SE - just a connector and two screws. You need to either note the position it was in, or know how to recalibrate it (just measure the resistance between PINs and then position so that it reads the same - AFAIK). No need to take the intake off.
 

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'84 500 SEC Euro 040 black Lorinser 2005 sl500
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hmmm, I had it removed on my 420SE - just a connector and two screws. You need to either note the position it was in, or know how to recalibrate it (just measure the resistance between PINs and then position so that it reads the same - AFAIK). No need to take the intake off.
Apparently they fail with extended use due to wearing out part of the material on the back of the unit. Bosch had discontinued them but I believe they are now available again. I needed to add one of these to my gen I 500 which did not come with one just to have the retrofit trip computer added to my car.

Not sure if different models used different meters but here is a quick reference on how to adjust one once replaced:

SG-Motorsports Air Flow Meter Potentiometer Replacement
 

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2012 CL550 4MATIC Coupe
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Apparently they fail with extended use due to wearing out part of the material on the back of the unit. Bosch had discontinued them but I believe they are now available again. I needed to add one of these to my gen I 500 which did not come with one just to have the retrofit trip computer added to my car.

Not sure if different models used different meters but here is a quick reference on how to adjust one once replaced:

SG-Motorsports Air Flow Meter Potentiometer Replacement
I knew Greg would know! He knows Gen I's better than anyone I know! Thanks Greg!
 

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'84 500 SEC Euro 040 black Lorinser 2005 sl500
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No problem, but it is actually a gen II part that I had to figure out how to add to a gen I that does not come with it nor the place on the air flow meter assembly to place it. To place one on a gen I, you need to replace the stock gen I assembly with a stock gen II air flow assembly all the way down to the boot.
 

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1983 300 SD, 1991 420 SEL, 1979 300SD
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on my old 86 420 sel i took that thing apart (it's definitely a TPS but mercedes calls it something else and i too can't remember the name for it) after reading somewhere that you can use a rubber eraser and clean up the contact area. i remember it actually worked; it just had crap on it but it wasn't like the area was worn out. maybe try that first, just be careful not to bend the metal arm
 

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Discussion Starter #13
on my old 86 420 sel i took that thing apart (it's definitely a TPS but mercedes calls it something else and i too can't remember the name for it) after reading somewhere that you can use a rubber eraser and clean up the contact area. i remember it actually worked; it just had crap on it but it wasn't like the area was worn out. maybe try that first, just be careful not to bend the metal arm
Thanks. I'll try that. On my previous car it really had scratches and worn out places on the contact area.

What were your symptoms when it was failing?
 

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Discussion Starter #14
So, the P/N 2015405645 which I found is probably only for the cable to the sensor, but not the sensor itself. I can't find the sensor anywhere in EPC :(

I'll keep looking for Bosch number 3 437 224 03, but I don't think I can get it.

Any ideas? Is it at least the same on other engines, or V8 M116/M117 specific?
 

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1986/1990 W126
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Hmm this is interesting, its a job I've had on my list of things to do, but everywhere I've checked it says intake off.
I heard about the calibration bit though.
 

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Thanks. I'll try that. On my previous car it really had scratches and worn out places on the contact area.

What were your symptoms when it was failing?

the car would have a "hiccup" when accelerating, not always but enough to be annoying.
 

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Discussion Starter #19
the car would have a "hiccup" when accelerating, not always but enough to be annoying.
Hiccup as in "loses power, wants to die or dies"? That's what mine does, but runs fine otherwise (at least from an oscilloscope perspective), just a little too lean all the time
 

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yeah it would just cut out for a second, not dying or anything. kinda like it didn't get spark for a second
 
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