W124 220 coupe
Thread Starter
Newbie
Joined: May 2014
Posts: 3
Likes: 0
From: Cyprus
Mercedes 220 coupe W124
W124 220 coupe
Hi just joined this site and wonder if anyone can help with my problem..ok details of my car: 1995 W124 220 coupe auto
Engine type
M 111 E 22 / 111.960
Fuel system
microprocessor-controlled injection system with hot-film air-mass sensor (HFM)
Now for my problem..for some reason Mercedes have an upshift delay valve , which simply means when the car is cold it will hold it in gear so the cat can warm up quicker, this works fine, however when it has reached normal tempereture and I turn the car off and on again it will hold in 2nd to 3rd and will only change up to 4th when I have reached 3500 revs or I downshift with the auto gear stick and imediately put it into drive again then it will shift into 4th..once its done this twice it will then run perfectly.. Also it will not start first time when cold once it has reached temp it will start first time on the button, it will also start first time even when it has dropped to 40deg temp only time it has problems starting first time is in the mornings when its left overnight.
I have rewired the deteriorated wiring soldered and heatshrink both for the harness and the wiring on the throttle body both were not that bad actually...I have purchased a new Mass sensor, a new upshift valve..a new 4 pin engine temp sensor< (ECT)..a new OEM OVP relay. I have pulled the vacuum pipe from the upshift valve and did a vacuum test and it does not hold the vacuum, however i did this when the car was hot so maybe I should try it when cold..based on this I am waiting for a modulator or regulator which fits on the outside of the gearbox and the vacuum pipe i mentioned goes from the upshift valve to this modulator..
I would like to know if anyone has a wiring diagram of the ECT 4 pin sensor and where exactly does each wire go to..I know wire 1 and 2 go to the large plug behind the battery, I have traced the other wires 3 and 4 which go to a box on the right inner wing as you face the car and when I removed the box cover it connects onto a plug and the wire from that plug goes behind the battery and through the firewall, but do not know where it goes to from there, perhaps to the gearbox?
The resistences from the ECT are all correct..
Coolant temperature
Resistance
20 degrees C
2500 Ohms ±5%
80 degrees C
300 Ohms ±5%
however I hope I have connected the new plug I purchased for the ECT correctly. as I discovered pin 1 is earth..pin 2 is live..and apparently pin 3 and 4 can go either way..I am getting 4.9v on pin 2 which is correct and 1v going back to computer from pin 3 or 4 not quiet sure now but the last pin is also showing 4.9v not sure why..although I have been told that the 4 pin ECT are two identical ones within one sensor so perhaps that one should show up to 5v.
There must be someone out there that can help me please pretty please
Thanks
Chas
