Failure to heed warnings:
When last posted the 74 280c had been tuned up by myself and it ran great. As a side bar I stated that the condensor could not be had without ordering it from Germany, from the dealer at $42.00. I figured I keep the original at those prices.
Yesterday the car failed to start. it was obvious right away that the engine was receiving no spark. After checking the ignition wire, points, rotor etc. I could not figure out why it was getting no power to the plugs. I then remembered Gympie and Chuck Taylors warning that its best to lose the condensor, as it causes "greying" of the points. Well the car ran so good, I felt there was no need to just discard it.
Checked the condensor, it was shorted out. Threw it away, car started immediatley.
So, I paid the price for not heeding the warning. My questions are:

Why is the condensor on this engine a detriment while a necessity on every point ignition automobile since these dinosaur
ignition systems roamed the earth?

"Greying" of the points means?

__________________
Paul Varrieur
1974 280c
1972 Chevrolet El Camino
1987 BMW 325i
1990 BMW 525i
1996 Harley Davidson Road King
1999 Lexus RX 300

The offical name of the ignition system in which we have is called: Breaker-controlled transistorized ignition. Most of the work is done by transistors in the switch gear, or the box on the inside driver fender well.

Calling it a grey layer was incorrect. Acutally their are two types of layers.

The first is the Blue Layer:
The blue layer (tungsten oxide) is formed by the arch ocourring during the closing stage and the resulting burning of the contact layer. This arch is above caused by the discharge of the anit-interference capacitor in the ignition distributor.

A large closing angle (small contact spacing) favors the intensity of the arch and tereby the formation of a layer.

The Second is the Dark Grey Layer:

The dark grey layer is the rusult of burnt grease, oil or dirt particles formed between the breaker points.

Basically, the condensor was placed in the system to prevent radio interference, it is not needed by the ignition system. You might want to keep the green wire with connection. This is the one Chuck offered to send you if he has not already.

It is also important to check the two resistors which are located near the radiator to see if they are within spec. I think the silver one is 4 ohm and the blue is 6 ohm or vice versa. Also, insure you have a Bosch Blue coil installed. All are important for a "balance" for proper spark.

Thanks for the reply
sounds like the design of the system became the achilles heal. It is amazing to me that a condensor will end up causing such problems. The "Grey" layer is supposed to be controlled by the small plastic cover for the points I guess, since it is there to keep the aforementioned oil/grease/dust off of them.
I can't keep the Green Wire since it never existed on my car. Like a lot of cars of this age, it has been worked on by shade tree mechanics who have a better idea. The Ignition wire from transister box has been cut three times. As mentioned before, with its proprietary connector at the transister box, it is only available from Mercedes Benz by purcahsing the entire distributor. I may very well try to locate a Distributor from a donor junker somewhere (with wire) since I still cannot get the car to time out @ 4 degrees atdc. I feel that the mechanical advance might be causing this hiccup.
I will check the resistors, I assume these are the two on the left fenderwell close to the radiator.
The car has the Bosch Blue Coil.
Next up, the dreaded cable shift indicator repair.

__________________
Paul Varrieur
1974 280c
1972 Chevrolet El Camino
1987 BMW 325i
1990 BMW 525i
1996 Harley Davidson Road King
1999 Lexus RX 300

Paul,
Am confused as to which proprietary wire you are needing. Out of the switch gear box there is one connection to the harness and another green wire going to the capacitor. The green wire /w the capacitor are detachable from the distributor. This is not fixed into the distributor and should not be only available with a new distributor.

I'm going junking today for parts. If you would like me to pick you up a distributor email me know of a couple 110's that have them. Going to get pair of Euro lights off another 110.

Do yourself a favor . . . get a Pertronix Breakerless Ignition Kit . . . and forget about points . . . about 60-90 bucks . . .

http://pertronix.com

IMHO, would never use a Pertronix system. Too many problems. Do a Google search on the item and you will find far to many posts concerning installation and running problems. For the price of a set of breakers being 5 bucks and changing once a year I can buy 18 years worth of breakers for 90 bills. Don't think a pertronix would even last that long.

Well I'll tell ya . . . I'm in the desert of So.California where temperatures can get up to 130F. I've installed dozens of Pertronix kits with very little problems if you FOLLOW THE DIRECTIONS.

They have an IGNITOR II unit which is BULLETPROOF. It has SMART technology which monitors and corrects dwell and shuts itself down if the key is left on with the engine off . . .

They're really nice people to do business with, especially since they're 45 minutes from me. I've had them custom modify Ferarri and Lamborghini distributors for me for as little as $250.00 which to this day I've never had to touch . . .

Thanks for the petronix info. At this point (no pun intended) I am going to give the breaker points one more try. I'm not old school or anything like that, but I would love to get this distributor tuned properly. It has become a challenge.
I will resort to the petronix system however if i find nothing wrong with the mechanical advance.

__________________
Paul Varrieur
1974 280c
1972 Chevrolet El Camino
1987 BMW 325i
1990 BMW 525i
1996 Harley Davidson Road King
1999 Lexus RX 300

Paul,

I'm normally on the Diesel discussion, but your post got my attention.

My Mother-in-Law has one of these with the Calif emissions spec. and that poor M110 engine is gagging on its own fumes.

2 years ago I was able to find a condensor for one of these at a
local autoparts store in the LA area. You might be able to find one
in the area still-

As for the timing, 6 degrees ATDC seems to have been chosen for emissions reasons, and that's what the Calif cars are supposed to be set to. ...But I know that if you get the timing set at 14-16 degrees before TDC (which is more realistic for a gas engine anyway), this car really wakes up. Try it, you'll like it.

The reason, as I understand it, for the retarded timing was to force a lot of unburned fuel into these thermal reactors (not cat convertors), that are bolted to the exhaust ports. The combustion of the fuel there was supposed to raise the exhaust gas temps enough to eliminate some emissions. In a Calif car, all it does is to turn an otherwise neat car into a gas-gulping slug. I hope yours does not have those thermal reactors on it!!

__________________
Nate Stanley
(Currently Benzless)
1985 F-250 6.9l 170K
2009 SCION XB 36.5K
2003 LS430 78K
2012 Kubota B 2320

All's well that ends well.

Sorry to have dropped the ball on the green wire. I will check tonight.

Gympie and I agree to disagree on the Pertronix - I think it (or the Crane) is a good move. The Crane unit that was installed in my 250C in 1988 is still working fine.

If you are going to keep the points, a couple of things may help.

1. Find a spare transistor unit and keep it in the car. They can die suddenly and leave you stranded.

2. At least once a month, clean the points with electrical contact cleaner and check the dwell. Another method is to slide a dollar bill between the points once a month - this tip courtesy of Steve B.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe