Need advice on deceleration air valve
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Newbie
Joined: Feb 2017
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w126 280SE 1984
Need advice on deceleration air valve
Hi all
I recently had to replace both solenoid vacuum valves for the aircon idle up and the deceleration air valve on my '84 280se. The aircon idle up works fine but I am uncertain how to test whether the deceleration air valve is working correctly. The valve itself is in working order but I am unsure about the circuit controlling the solenoid.
If someone can explain to me how and what components controls this circuit and how to properly test it I would be much obliged. I have no drivability issues but I'd like to know that my fuel efficiency is as best it can be.
I recently had to replace both solenoid vacuum valves for the aircon idle up and the deceleration air valve on my '84 280se. The aircon idle up works fine but I am uncertain how to test whether the deceleration air valve is working correctly. The valve itself is in working order but I am unsure about the circuit controlling the solenoid.
If someone can explain to me how and what components controls this circuit and how to properly test it I would be much obliged. I have no drivability issues but I'd like to know that my fuel efficiency is as best it can be.
Newbie
Joined: Oct 2018
Posts: 14
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From: Melbourne, Australia
1984 280SE W126, 1982 280E W123
I'm pretty sure you'd be referring to the " Temperaturregler" which is a module that looks like the "Tempomat" (Cruise Control) Module (an aluminum box with a 14 Pin Plug on the end...I think it's 14 pins) and you'll find that under the dash on the passenger side, you'll need to remove the "knee pad"... the carpeted part that sits below the glove box between the center console and the door.
Similar to the issue that often plagues the Tempomat module, these Temperaturregler are well known for suffering from "Cold Solder" which is when the solder used to join the various resistors etc to the circuit board become almost microscopically cracked due to heat and age, this causes with intermittent connections or permanently disconnections. Thankfully, if you're handy with a soldering iron, all you need to do is re-melt the solder points on the rear of the circuit board which renews their connections.
The above of course is assuming you've double checked your vacuum liners to and from the solenoids are correctly routed and have sufficient pressure (i.e. no vacuum leaks in the peripheral vacuum system at all).
I'll post a picture and part number shortly.
Similar to the issue that often plagues the Tempomat module, these Temperaturregler are well known for suffering from "Cold Solder" which is when the solder used to join the various resistors etc to the circuit board become almost microscopically cracked due to heat and age, this causes with intermittent connections or permanently disconnections. Thankfully, if you're handy with a soldering iron, all you need to do is re-melt the solder points on the rear of the circuit board which renews their connections.
The above of course is assuming you've double checked your vacuum liners to and from the solenoids are correctly routed and have sufficient pressure (i.e. no vacuum leaks in the peripheral vacuum system at all).
I'll post a picture and part number shortly.
