How Many Relays 230SL Has??

[alchemist]

Gentlemen:
I am new to this forum but not to the MB forum. I recently purchased 1967 230SL and found out that the previous owner has replaced the original engine with M130. This caused some modification of the electrical wiring. I noticed that there are only 2 relays on the driver side fender by the washer bottle. I keep reading about can looking relay which is missing from my SL. Currently I have only 2 relays: a voltage regulator and CSV relay with 4 prong. I found a plug with 3 prongs beside these relays but it is not hooked to anything. I would appreciate telling me if I am supposed to have 3 relays or only 2. If so, where can I purchase the can looking relay and what is its function? I will enjoy this forum and I hope to be an active member.

[ctaylor738]

If I remember correctly, a 230 would have four relays by the brake booster:

One 4 pin for the cold start valve
One 4 pin for the injection pump full rich solenoid.
One round ? pin for the hot start activation of the csv
One large for the wipers

Cheers

CT

[ja17]

The M130 engine will take less relays.   You will need to check the number on the injection pump. Look for the metal tag with the number. We need the last two digits after the "R" (eg. R11,  R18 etc).  When we get this information we can tell you how many relays you have. Are you having any cold or hot starting problems?

[alchemist]

Thank you for your valuable input regarding my 1967 230 SL. My injection pump # is: R20Y. I assume that this pump is used for 280SL and it was installed when M 127 was replaced with the M130 engine. This is what I found as a result of the engine replacement:
1.   There are only 2 relays by the break booster, there is one plug with 3 prongs is lying around in that area. I assume that this plug is for the 3 prong can-looking relay. The relay         is missing.
2.   The injection pump has 2 solenoids, only the upper one has electrical hook-up, the lower is not hooked to anything.
3.   The throttle positioning sensor has no electrical hookup. I do not see any electrical cable lying around the sensor area.
4.   The ignition was recently converted to Crane transistorized electronic ignition, it runs cold on a fast idle with 2000 RPM for 1 hour without slowing down even at normal temperature. If I reduce the idle mixture screw, it dies. It is definitely running very rich. I am about to test if the CSV is leaking. However, the CSV test light comes on only for few seconds, indicating that the thermo-switch and relay are working fine.
Any comments on the # of relays, missing wirings and the fast idle will be appreciated. Thank you.

[ja17]

OK, yes the R20 is an early version injection pump for the M130 280SL.  You should have two starting devices on your engine. One is the "CSV" or intake "cold starting valve". This you have already found out and it seems to be working. The other starting aid on your engine is the "injection pump starting solenoid" .  This is the upper solenoid on your injection pump.  This solenoid should energize anytime the starter is engaged. You should check it with your test light also. The lower solenoid on the injection pump is a fuel cut-off which cuts the fuel supply during deceleration. Some refer to it as the deceleration solenoid.  It is basically an emission add on, which cuts emissions during deceleration. It is often left disconnected to prevent problems. Your 230SL should have no wiring for this deceleration solenoid. Leave it as is. Your car should be using  two relays to operate the two  starting aids you have on your engine. Check both starting aids.

If your car has a standard transmission, you will not have any wires going to the intake switch on your 230SL. In fact your original engine will not have a switch if this was the case.

Rich running can be caused by several different problems, but the fast idle points to some specific possibilities. First check the "WRD" for function. It is easy to check and fix. It can be stuck open causing the fast idle. Search up WRD. Get back with us if you have additional questions or need more info in the WRD (warm running device). Next, go through "The Linkage Tour" your intake valve may not be closing all the way. You will find lots of good information and photos here on that subject.  Once those two subjects are checked out, we can get into the "split linkage test" and how to use it to determine the injection mixture of your engine.

Sounds complicated, but it is not too bad. Just take one step at a time, ask questions and get back for more information as needed.

[Garry]

If I can get in my plug for full membership here, zalsaigh will not be able to access the Linkage Tour as he is not a Full Member.

Zalsaigh I think you have probably already realised what value this forum is but you will need to join the Group as a Full Member  ($30USD or 25 Euro. See here at the bottom of the Home Page.  http://www.sl113.org/ ) then you will have full access to all of the Technical Manual and additionally, will be able to access past Pagoda Notes and will receive the Pagoda World Magazine as it is put out.   One is due very shortly.


Garry

[alchemist]

Thank you Joe for your valuable advice and suggestions. I tested the IP top solenoid with a test light; the light came on for few seconds when the starter is activated. It is an indication that the solenoid and the relay are OK. It is the same case with the CSV, the light came on for few seconds when the starter is activated. However, I discovered that the CSV is leaking internally; this is why it was running rich. I took the CSV solenoid out and bench tested it, it works OK. The plunger comes in and out freely when activated with 12 V. So, I tested CSV mechanical valve (brass looking) by switching the ignition on in the run position and observe the valve visually while the solenoid out. Indeed, it leaks with continuous drops (more than 10 drops a second); it does not spray a strong stream. I cleaned the valve and the seat, it did not help. I poked it with an ice pick and I felt a spring action with the valve going in and out. It is evident that the valve is not stuck, yet it leaks.  Any suggestion for a fix is highly appreciated.