I don't want to answer for others but there's a coax cable for the crankshaft position sensor that runs to the electronic ignition unit. There's a spec for the resistance of that in the FSM

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The EZL switchable timing resistor sits near to the electronic ignition unit if fitted. Otherwise a resistor lives nearer to the fuel injectors (from the pictures I've seen). Note there can be two of these switchable resistors. There's one for the electronic ignition and one for the ECU. As far as I know the one at the ECU shouldn't be messed with - it has an anti-tamper wire fixing it.

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A high idle of about 1200 to 1500 rpm is meant to indicate an inoperable air idle control valve.

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To measure Duty cycle there are tips here

BOSCH KE3-JETRONIC MIXTURE ADJUSTMENT

If you don't have a handy Duty cycle button on your multimeter.

The "Duty cycle error codes" are not the same for all vehicle types - make sure you look in the correct section of the FSM to find out what they mean.

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I also think the DIY addition of the resistor didn't make a great enough change. If you look in the FSM for the effect of changing the coolant temperature into fooling the ECU to stay in a warm up phase (for example) you need kilo ohms and kilo ohms to do this. A few ohms probably hasn't made much of a difference. (Unless it has been wired in some way I don't understand!)

Bob
I want to make sure spark plugs are non resistor.
Yes the micro switch at throttle linkage.
Terminal #2 at EZL to ground to test if ECU is reading TPS. Terminal#2 is on
the four pole connector on ignition control module
near the X11.
Yes TPS is throttle position switch on front of throttle body.
Continuity at terminal #2 should be present only when return
spring is attached. Throttle plate should move slightly when spring is detached.
This was my problem, on the 92, and if you have replaced TPS I would check it's
operation.
Vacuum reading will let us know if there is a large leak.
I have a thread on Benz world 124 sedan forum (m103 high idle unless ICV disconnected)
It's on page #2 H.D. wrote in with helpful testing procedures.
Duxthe1 is correct ECU is missing a reading from a sensor.
Hope this helps
Paul

Note that there are / or can be two micro switches.

One is visible next to the accelerator wire that goes into the cabin and onto the accelerator pedal. (Remove air filter and you see it)

This one connects to the fuel pump relay and the CIS ECU

The other micro switch that is connected to pin #2 on the electronic ignition unit (left hand plug = sensors) is on the throttle valve under the air balance gubbins...

...this also goes to the CIS ECU but also goes to the ignition control unit (whereas the other just goes to the CIS ECU)


...I have a question about these two switches


Are they meant to operate at exactly the same time?

I have adjusted my throttle linkage as described in the FSM but the lower throttle valve switch operates before the top switch...

Stretch
On my 92 the micro switch at the accelerator cable
disconnects first. After more movement of the
linkage the TPS disconnects. However, I don't know if
the linkage is adjusted properly.

Paul

dux... I do not have any fault codes other than for the seat belts at the test port just to the right of the battery unless you know of another place ??

I dont remember if I measured the air flow pot or not after I popped a new one on.
Weather has sure not been cooperating much. Sunday was a good example. High 60's with 20 to 40mph wind gusts. Hard to keep a hood up in that.

Voltage update. At rest not even the key in the igition. 12.2vdc
X11 at rest 0vdc
Key on at X11 10.4vdc

New spark plugs are non resistor as were the old ones. Car ran and idled correctly after the new plugs were installed.

EZL location found on youtube. No I have not done any testing there.


Ive only seen the micro switch just to the rear of the fuel distributor and it tests good.

What you are measuring at the x11 is an error =>

Thanks I thought it was like that

#2 ground
#3 signal or hot

X11, driver side fender up high forward for the strut housing

Does this help?

http://www.benzworld.org/forums/atta...s-x11-pins.jpg

Thats the same X11 reference Ive been using... soo thanks for confirming.

Temps have been great... its just the rest of the weather that keeps me from the M103.

Last few days, high 60's but windy and rainy
Today we added tornado warnings....