Hi guys,

What does part number 59 on this diagram do please?
Its described as TEMPERATURE SWITCH TO MUFFLER FILTER.

Many thanks

Must be a 16V engine?

The system uses 2 intake air temp sensors, 1 for the fuel system & the other to regulate ignition timing.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Hi MB Doc, you are correct! Its for a 16v...
So what sensor controls the ignition timing?

The "brass" 3 wire sensor (#59) is for ignition retarding above 25C.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Your a genuis, i think this might explaina lot of things!
My car has been at my local Mercedes dealer for nearly a month now...

Problem has been under WOT the car hesitates/jerks, call it what you will...Under normal driving conditions its fine.

They have checked everything like the K-Jetronic etc and its all fine. Infact 90% of it is new. New fuel distributor, EHA, Injectors, ECU, Fuel pressure regulator, Fuel pumps, Accumulator.

So anyway they are now going to put an Ignition control module in there and see if that makes a difference.

But this sensor, number 59 might be the culprit? My car has no other issues at all. Starts fine, hot or cold...Idles fine, although in reverse sometimes the idle drops ever so slightly then goes back up. its an auto by the way.

No one can figure it out and to make matters worse my friend has the same car with an autobox with the same problem! He has lived with the jerking on kickdown (WOT) for the last 7 years!

Of course you can eliminate ALL of the "fuel system" electronics by driving the car with the EHA disconnected.

At that point you would think that the ignition is causing the problem.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

EHA is new MB Doc.

Well just got a call from the dealer saying the part is on back order.

If its the ignition shall i change item number 59? All leads and supressor plugs for the ignition are new.

What would be the symptoms of a bad Ignition module and/or Item number 59 please?

Can i definitely rule out a gearbox problem?