123 ignition

[Ron.K]

I was fortunate enough to attend the 2015 PUB. Dan Caron came over to my car (1970 280sl) and diagnosed a defective switch gear as well as my relay that advances the distributor at 2000 rpm also defective. Beckmann electronics has quoted me $360.00 to repair the relay and they do not repair the switch gear. I can't find one to buy. So, with talking to many people at the PUB, I have decided not to repair these parts, and to purchase the 123 ignition. It should be here on Friday.
I have been reading the 123 ignition page on this site, and it says that if your emission systems are not working, you require a different throttle body vacuum pick up.
The 123 ignition has a vacuum port that needs to be connected.
Can someone tell me what is required and how do I convert this properly. My 280 does not have the relay on the back of the injection pump, but does have the 2 black relays adjacent to the vacuum switch.

Thanks.

Ron.

[kampala]

Ron,

Since it reads like your car is a late USA model with transistorized ignition and all USA emissions (two black boxes, two-way valve, etc) and probably an 062 distributor, the change to a 123ignition is not as simple as earlier cars.  But achievable. 

I will try to explain --- but it's not easy without pointing to everything under the hood.   In addition, I am referring to the 123 that is pre-programmed ( with 16 or so presets)  not the 123-TUNE.   If you got the Tune unit, this may not apply.


I believe (others clearly believe differently, as you will read) that the 123 when set on program E (if I recall the program correctly) for the 062 dizzy requires that your relays and two way valve work properly in order for the 123 to get the proper vacuum at the correct RPMS.    The issue you have is that the throttle body on these USA late 280s is matched to the 062 dizzy and provides vacuum all-the-time, regardless of the rpms, always retarding unless interrupted by the two-way valve etc.  Program E, expects that vacuum will be controlled by the two-way valve and the relays.   

This said, you have a couple of ways of making the 123 work without repairing all your relays and two way valve and bypassing it all etc.

Some have simply connected the vacuum line as it comes from the USA model, vacuum all-the-time, throttle body directly to the 123, used program E and timed the car with a bit of extra advance and called it done.  This seems to work for some quite well.   For others, like me, not so much.  This is the easiest solution if it works for you.  The issue with doing it this way is that you may not be able to get 30+ degrees of advance at 3000 rpm and still have an advance at idle that is comfortable.   Your advance at idle may be too far advanced.  If you set your advance at idle at 8 BTDC, when you rev to 3000 you may not be able to reach 30 degrees BTDC.  Hence you may not get the power you would expect.  This is because your throttle body is providing vacuum all-the-time and continues to retard the dizzy --- and without the two-way valve and relays, the vacuum stays on and keeps retarding.  As you will read, some have no issue with this and their cars seem to run just fine.  This is the easy solution if it works for you.

For me, the above method caused my 280 to have less power in the higher RPMs and idle was not comfortable with extra advance. 

The other method is to replace the throttle body or modify your throttle body to a "European" throttle body which does not need the relays or two-way valve.  This modification is reversible if someone wanted to put everything back.  By changing (replace or modify) the throttle body you would use program 8 on the 123, which is for the 051 dizzy.  This modified or replaced throttle body only has vacuum at idle/low rpms so only retards at low rpms, hence giving you full advance to 30+ degrees at higher rpms.   You can recognize the different throttle bodies in the tech manual.  The one that I'm referring to (as modified) is the one commonly matched to the 051 dizzy that uses program 8 on the 123, has the vacuum coming from underneath the throttle body directly under the butterfly.  You can swap yours for this type or you can plug your vacuum port on your current one and add a vacuum port on your throttle body at the proper place in order to only have vacuum at low rpms.  If you are not comfortable drilling a precise vacuum port into your throttle body, send it to one of the experts, I know Gernold at Sl-Tech has done this for others.  I modified mine myself as I used my 250sl throttle body as a model and matched the port location and hole size exactly.  If you do this yourself, you need to be precise so only power up the drill if you have a model to match to.  If you want to replace the throttle body instead of modifying and find a correct one, you need to make sure it's for an Automatic or Manuel depending on your car.

With a modified throttle body, the 123 set on program 8, and the vacuum line run directly from modified throttle body to the 123, my car runs much better.   By doing this, you are basically making the Late USA car work like a Euro car or an earlier non emissions USA car.

I do hope this makes some sense --- again, only pull out the drill if you fully understand and have a sample to match.

I hope others provide opinions as well --- my experience seems to differ from others so it would be good for you to get more feedback.

Best,

[Naj ✝︎]

Hi, Ron,

Do a "VW" 

In my view vacuum retard does nothing for the engine or performance. It was introduced to meet NOx emissions.

On my US 1970 car, I have blocked the vacuum and have not noticed any ill effects.

To improve engine performance, look for a vacuum advance throttle body and use the appropriate advance curve on the 123.

Just my £0.02p

naj

[Benz Dr.]

Sort of, but not quite.

Late USA models use all of that switch gear which will pull the distributor timing to about 3 degrees ATDC at idle. At around 2,200 RPM the vacuum is switched off and the distributor will advance about 20-22 degrees all at once. Removing the vacuum system will give you about 10 degrees of mechanical advance only; I can't imagine how that's any kind of improvement.

 Everyone seems to get stuck on 30 degrees advance at 3,000 RPM. This is what a 051 unit will give you but I think there's been no allowance for 8 degrees of timing at idle which should always be added to the distributor advance of 30 degrees for a total of 38 degrees. Anything less and it will drink fuel and have no power. You may think your car is making good power until you drive one that's set up to max specs.

Ron, you can also use the early 280SL throttle body if you go to the 051 settings because you will want the fittings for the throttle body heater. Because your speed relay quit working, I set your idle timing to about 8 degrees. This made your engine ping under light load and lower engine speeds although it seemed fine at road speed. Setting the timing to about TDC would reduce pinging but it would also reduce power somewhat. 

[twistedtree]

I'm confused. Aren't both the 051 and 062 distis vacuum retard, so wouldn't the throttle body vacuum ports be in the same place on both?  I thought the only vacuum advance distributors and throttle bodies were early 230s?

[Ron.K]

Thank you all for your help. I have added some photos of my throttle body. Since I do not have another throttle body from an older 280, I will have to drill a port in mine, if I find that the performance is not what I like. I will try to connect the vacuum line from my throttle body first, directly to the vacuum port on the 123 and see how it performs. Do I run a new vacuum line from the throttle body port directly to the 123 or do I use the existing line going to my distributor and cap off the emission vacuum switch.

Ron.

[Benz Dr.]

I'm confused. Aren't both the 051 and 062 distis vacuum retard, so wouldn't the throttle body vacuum ports be in the same place on both?  I thought the only vacuum advance distributors and throttle bodies were early 230s?

They're both vacuum retard but the 062 uses switch gear to turn the vacuum signal on or off depending on RPM. 051 distributor is all mechanical in that the vacuum signal alone advances or retards the ignition timing.

Running the line from a late 280SL throttle body will only give you a constant vacuum signal not much affected by throttle opening so you will have a constant retard condition on the distributor. You need the switch gear to shut the vacuum off so the distributor will advance at 2,200 RPM. It's switch gear or a different throttle body. Since you already have all of the parts to run the switch gear, I would get the speed relay rebuilt and I would not start drilling into a perfectly good throttle body. The placement has to be exact - don't go there.......... 

[awolff280sl]

Dan, when you set the idle timing to 8 degrees, that is with the vacuum disconnected, correct?

[twistedtree]

They're both vacuum retard but the 062 uses switch gear to turn the vacuum signal on or off depending on RPM. 051 distributor is all mechanical in that the vacuum signal alone advances or retards the ignition timing.

Running the line from a late 280SL throttle body will only give you a constant vacuum signal not much affected by throttle opening so you will have a constant retard condition on the distributor. You need the switch gear to shut the vacuum off so the distributor will advance at 2,200 RPM. It's switch gear or a different throttle body. Since you already have all of the parts to run the switch gear, I would get the speed relay rebuilt and I would not start drilling into a perfectly good throttle body. The placement has to be exact - don't go there.......... 

OK, I follow that there are valves that block/open the vacuum line at various times, and that it needs to be matched to an 062 disti that is expecting such blockage/opening.

But is the vacuum port in the throttle body actually different between a throttle body meant for an 062 and an 051, or is all the difference in the vacuum line, valves, and disti?

I would expect the port in the throttle body to be the same, but don't know.  If they are the same, I would think you could run a vacuum line directly from the throttle body to the 123, and the set the 123 to act as an 051 replacement and the advance curves would then properly match an 051 with happy results.

[Ron.K]

To answer your question about timing the car with the vacuum either disconnected or connected, we timed the car at the PUB with the vacuum line always connected.

Another question I have is when I install the 123, I have existing wires which are connected to the ignition coil. What do I do with them? Do I leave them connected at the coil terminals and add  the wires from the 123? Looking at the wiring diagram in the tech section of the late 280's, I have 2 ballast resisters wired in series through the switch gear box. The 123 site says I can remove the ballast resisters to get the full 12 volts, does that mean to place a jumper wire across each of them? Also My switchgear box acts up when it gets warm, and causes my engine to die, so it needs to be bypassed as well.

Ron





 

[Cees Klumper]

On the ballast resistor point, I did simply take mine out, and connected the wires (in/out) together when I installed my 123.

[Benz Dr.]

Dan, when you set the idle timing to 8 degrees, that is with the vacuum disconnected, correct?

I leave everything connected and set to 8 degrees BTDC on 051 type distributors. I look for how the distributor is working in full function mode which means all lines connected. Ideally, you want about 38 degrees of advance at or before 3,000 RPM. Some units will top out at 2,700 RPM.  That's OK as long as there's no evidence of pinging.   

[Benz Dr.]

OK, I follow that there are valves that block/open the vacuum line at various times, and that it needs to be matched to an 062 disti that is expecting such blockage/opening.

But is the vacuum port in the throttle body actually different between a throttle body meant for an 062 and an 051, or is all the difference in the vacuum line, valves, and disti?

I would expect the port in the throttle body to be the same, but don't know.  If they are the same, I would think you could run a vacuum line directly from the throttle body to the 123, and the set the 123 to act as an 051 replacement and the advance curves would then properly match an 051 with happy results.

Good question. Yes, there is a difference between these throttle valves. Late USA throttle bodies are open to constant vacuum while the engine is running. The speed relay, thermo switches, and vacuum switch over valve control when vacuum is applied or when it's shut off. Basically, the 51 has 20 degrees of mechanical advance and 10 degrees of vacuum movement. The 062 has 10 degrees of mechanical and 20+ degrees of vacuum. This is why you want the vacuum portion working because it makes up over 2/3 of the the total timing advance on a 062. 

[Benz Dr.]

I'm not very familiar with the 123 system but I'm sure you can run straight from your coil with no ballast resistors needed. For all intents and purposes, I imagine it would run similar to a 051 set up with switch over valve hook up depending on what setting you use. I'm sure others can add more to this.

 As I said at PUB, you can use any system you want as long as all of the parts match and work together as a complete unit.

[awolff280sl]

Thanks Dan, that's very straightforward and simple. Found that my 051 was timed at 30 @ 3000 and 0 @ idle. Redid it as you said and then re-did the idle mixture.
The car has more "pep" now!

[Ron.K]

An update on the 123 install. This past weekend, I installed the 123 into my car. I did have a couple issues that I would like to share because it might help others.  The first thing I did was to get the motor to TDC. Then I  set the 123 to E. I then removed the old dizzy, cut the wires to the condenser but left the plug wires on the old cap. I looked down into the shaft and saw the spring which I then removed. When I purchased the 123 from the U.S. supplier I called him on the phone and asked him about the spring, he said do not put the spring back in, it is not required. He said guys have been trying to put the longer spring in and if it's not perfect it damages the 123. He's had some come back. What does this spring do anyway? When I put the 123 in and pushed all the way down making sure the rotor is lined up with the notches, I found that I could turn the rotor about a quarter turn which is not right. I pulled it out and tried again, this time I turned it 180 degrees and it went in, and I had no play on the rotor. Next I found the wiring diagram on the transistorized ignition for my car on the site. I want to bypass both ballast resisters and the switch gear box under the battery. So I cut the black wire which goes to the first ballast resister, attached another black wire to the end of it and ran it to the plus post on the coil. I removed the black wire that was on the plus post which came from the 2nd resister. This now has bypassed it all, which is what I want. I then connected the red wire from the 123 to the plus post of the coil. I set the 123 up with the led as per the instructions, then attached the black wire from the 123 to the neg on the coil along with the existing neg that went to the body for a ground. I then connected the spark plug wires to the new 123 cap making sure that the rotor which was pointing to the number one cylinder, is connected back to the same post. then the rest with the firing order. The high voltage came next, and now I'm ready to start her up. I turn the key, it cranks but does not start, it does not fire. What the Hell!! I have 12volt to the coil, but when I pull the center coil wire off the dizzy and hold it close to a ground and crank the motor, no spark. What is wrong? Well a phone call to my mechanic friend and he says I have to remove the neg wire which was on the coil that goes to the ground. So I did, and the only wire on that negative post of the coil is from the 123. Tried again and it fired right up.Set the timing to 8 Deg BTDC, blocked the old vacuum line, and took her for a spin. The motor used to knock upon acceleration and now it doesn't, but I don't have the power that I used to have. It only advances to 20 degrees when I rev it. I have to set the fuel/air ratio up again because the plugs foiled up. I sent the rpm relays to Beckman tech for repair. That's my story for now.

[Benz Dr.]

Andy,

Timing your engine to 38 degrees from 30 degrees will make a big difference. It's those last couple of degrees that are so important.

[Benz Dr.]

An update on the 123 install. This past weekend, I installed the 123 into my car. I did have a couple issues that I would like to share because it might help others.  The first thing I did was to get the motor to TDC. Then I  set the 123 to E. I then removed the old dizzy, cut the wires to the condenser but left the plug wires on the old cap. I looked down into the shaft and saw the spring which I then removed. When I purchased the 123 from the U.S. supplier I called him on the phone and asked him about the spring, he said do not put the spring back in, it is not required. He said guys have been trying to put the longer spring in and if it's not perfect it damages the 123. He's had some come back. What does this spring do anyway? When I put the 123 in and pushed all the way down making sure the rotor is lined up with the notches, I found that I could turn the rotor about a quarter turn which is not right. I pulled it out and tried again, this time I turned it 180 degrees and it went in, and I had no play on the rotor. Next I found the wiring diagram on the transistorized ignition for my car on the site. I want to bypass both ballast resisters and the switch gear box under the battery. So I cut the black wire which goes to the first ballast resister, attached another black wire to the end of it and ran it to the plus post on the coil. I removed the black wire that was on the plus post which came from the 2nd resister. This now has bypassed it all, which is what I want. I then connected the red wire from the 123 to the plus post of the coil. I set the 123 up with the led as per the instructions, then attached the black wire from the 123 to the neg on the coil along with the existing neg that went to the body for a ground. I then connected the spark plug wires to the new 123 cap making sure that the rotor which was pointing to the number one cylinder, is connected back to the same post. then the rest with the firing order. The high voltage came next, and now I'm ready to start her up. I turn the key, it cranks but does not start, it does not fire. What the Hell!! I have 12volt to the coil, but when I pull the center coil wire off the dizzy and hold it close to a ground and crank the motor, no spark. What is wrong? Well a phone call to my mechanic friend and he says I have to remove the neg wire which was on the coil that goes to the ground. So I did, and the only wire on that negative post of the coil is from the 123. Tried again and it fired right up.Set the timing to 8 Deg BTDC, blocked the old vacuum line, and took her for a spin. The motor used to knock upon acceleration and now it doesn't, but I don't have the power that I used to have. It only advances to 20 degrees when I rev it. I have to set the fuel/air ratio up again because the plugs foiled up. I sent the rpm relays to Beckman tech for repair. That's my story for now.

Sounds like you're coming along well. 20 degrees of advance sounds right at this point. What you are seeing is 10 degrees of mechanical distributor advance without any vacuum signal. This is why I tell people NOT to disconnect any vacuum lines from the late USA system.

[wwheeler]

One thing I was told concerning the 123 ignition is NOT to test a spark plug lead by grounding without having the spark plug in it. They said it creates a big problem for the electronic brain and can damaged it. Not sure if grounding the coil has the same effect, but might ask.

[teahead]

Can someone post pictures of this "switch gear" on the USA late models?

I have an 062 and just wondering before converting to the 123, whether to see if that stuff is all working or not. HOw to tell?

Also, what SHOULD the timing be for an 062 w/123?  30 @ 3000RPM?  More?

[teahead]

Looks like I'll get the 123.

The screw to hold down the points is stripped.  Good excuse to go all electronic and get a distributor.  $$$

I'm sure I can repair (maybe) the 062, but will just have it for resell of the car someday.

[Benz Dr.]

Very easy to tell if the late ignition system is working. Place your hand on top of the vacuum switch over valve and throttle up until you reach 2,500 RPM. You should feel a small vibration when it switches over. If you feel nothing, good chance it's not working.

[teahead]

Very easy to tell if the late ignition system is working. Place your hand on top of the vacuum switch over valve....

Is that #9 here?

[Benz Dr.]

Yup, number 9. It will click and you should be able to feel it. The click will happen twice; once as you pass 2,200 RPM and then as it passes that speed going down to idle.

[teahead]

This coil ok w/the 123 ignition?

Use a ballast resistor or no?