Author Topic: 2 way valve operation.  (Read 3529 times)

Ron.K

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2 way valve operation.
« on: April 27, 2016, 03:29:02 »
I have a 1970 280sl with the emission system. At the PUB last year, Dan Caron noticed that my 2-way valve was not working when the engine rpm was increased over 2400rpm. It was not getting 12 volts. He suggested to send both the speed relay and relay box in for repair, which I did. Turns out the speed relay was defective and the relay box was good. They repaired it and last weekend I installed both. I still do not get 12 volts at the 2 way valve when I increase the rpm. I looked at the wiring diagram on the emission page and noticed that the transistorized relay box under the battery is also in the circuit. Last summer I also installed the 123 ignition system into the car which does not require the box under the battery, so I bypassed it. Does anyone know how to now wire this 2-way valve circuit with the transistorized box not in the circuit?

Ron.K

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Re: 2 way valve operation.
« Reply #1 on: April 29, 2016, 03:04:45 »
Well, last night I reviewed the wiring diagrams for the emission system so I fully understand how things operate. Tonight I had a plan on how to troubleshoot this. I checked for incoming power to the relays, which was fine. I checked the 17 deg switch wiring and the 100deg switch wiring, all checked out ok. I started the car, pulled the wire off the 100 deg switch, put a jumper on the wire to ground and the 2 way valve clicked open and the motor RPM increased, because it advanced the distributor, perfect... I tried the same thing on the 17 deg switch and it worked as well. Great. So now I increased the RPM over 2400, but the 2 way valve does not open. Can anyone tell me how the speed relay detects the rpm?

jeffc280sl

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Re: 2 way valve operation.
« Reply #2 on: September 18, 2016, 23:47:17 »
check the forum under my name.  Also check the tech manual.  I did a complete write up a few years ago.

Benz Dr.

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Re: 2 way valve operation.
« Reply #3 on: September 19, 2016, 03:37:14 »
Ron,
you really want this to work or you will loose 20 - 22 degrees of advance.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC