Ignition problem w114 - Page 2 - Mercedes-Benz Forum

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post #11 of 25 (permalink) Old 03-29-2014, 04:47 AM
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Originally Posted by kurt912 View Post
To be fair I was using the electronic ignition and new coil to replace the points, condenser, old coil and transistor module. If it had worked then I would not have started the thread. But since it's not at this point I'm thinking to repair the old configuration. But I see your point.

If I wasn't so cheap, I would have done the same thing with my 250. I didn't want to spend the money though.

A diagram showing how you wired everything might be helpful. It may highlight where things went wrong.




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post #12 of 25 (permalink) Old 03-29-2014, 10:40 AM
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Ignition problem w114

If you are going to try trouble-shooting the original configuration, this was my bible as I went through returning my 250 to its stock configuration. There are multiple tests you can perform (and report back results) if you have a multimeter.

http://www.sl113.org/wiki/Electrical/TransistorIgnition




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post #13 of 25 (permalink) Old 03-29-2014, 12:25 PM
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Quote:
Originally Posted by kurt912 View Post
To be fair I was using the electronic ignition and new coil to replace the points, condenser, old coil and transistor module. If it had worked then I would not have started the thread. But since it's not at this point I'm thinking to repair the old configuration. But I see your point.
You are much better off by installing the electronic ignition and getting rid of the transistor modual, points and condenser.

Lets take this step by step and see if we can find the problem.


You can actually leave the ignition on for about 30 seconds without any issues.

So with the key on, how many volts are you getting at the coil?

If you are getting power there, I am wondering if the problem is from the top of the coil to the distributor.

The distributor cap has a notch that is supposed to fit onto the distributor only one way, but it is easy to not set it correctly into the notch and have the cap installed wrong. I did this the frist time I got the car. Also, what is the condiditon of the distributor cap and rotor? Are there any cracks in the plastic? Does the metal part on the rotor look like its worn down?

What about the condition of the wires?

Just before I installed my hot spark, I put new wires, distributor cap and rotor just to be certain that there would not be an issue there.

Another thing that I had to do, was grind down the metal "sleeve" on each spark plug wire underneath the rubber boot where it connects to the spark plug. What was happening was the sleeve was too long and stopping on the sparkplug "nut" and it was keeping the sparkplug wire from making a tight connection onto the spark plug. After grinding about 1/4" off, the plug wires not hold on very tightly to the plugs.

If you could take some pictures of all of these things and post, we could all get a better look at it.
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post #14 of 25 (permalink) Old 04-01-2014, 04:51 PM Thread Starter
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Hi Luna. I believe I was getting around 11+ volts with the key on. I guess new wires won't hurt (or cap and rotor).
I'm aware of the notch on the dizzy cap so that couldn't be the problem. IF the electronic ignition is good then it's wires or cap I guess. But if it's wires or cap then I made the wrong guess and didn't even need the electronic ignition.
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post #15 of 25 (permalink) Old 04-01-2014, 06:17 PM
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I tested for spark out if the coil by holding the end of the ignition wire that normally connects to the cap (other end connected to the coil) by holding the ignition wire close to some body metal while cranking the starter.

That doesn't eliminate the ignition wire as a possible problem, but does eliminate the cap and plug wires.

If using the standard transistorized ignition, the voltage to the coil should go a little nuts while cranking, fluctuating between 0 and 12+ volts. On a volt meter it might just seem to say something like and unstable volts though.

If using HotSpark, I believe you want a constant 12 volts at the coil + and the ground is interrupted via the HotSpark.

I'm Not sure, but that's the way I understand it.


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post #16 of 25 (permalink) Old 04-02-2014, 09:03 AM
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when the original transistor ignition failed , i would have set the car up as a pre 69 [ standard ignition ] just pointes / condensor and the right coil . used to do it in the old days , and it worked very well .
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post #17 of 25 (permalink) Old 04-02-2014, 11:46 AM
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Originally Posted by agillot View Post
when the original transistor ignition failed , i would have set the car up as a pre 69 [ standard ignition ] just pointes / condensor and the right coil . used to do it in the old days , and it worked very well .

That's how my 1970 was setup when I got it. There was a transistorized coil in there, and the car would run with that coil wired up the way you mention (12v to +, and green points wire to -), but the points were fried and the spark was not a good quality spark. The secondary resistance on the coil was bad when I tested it. In my case, I put the switchgear I found disassembled in the trunk back in the car and discovered only the coil was bad, and the car runs well with a good coil. I don't know if the system was wired "old points style" due to the coil being bad, or if that made the transistorized coil go bad. It definitely fried the points though. They were all green and charred and crusty.






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post #18 of 25 (permalink) Old 04-08-2014, 08:51 AM
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first , put pointes back in , use a condenser num 000 156 81 01 , coil num 000 158 49 03 , a 000 158 08 45 ballast , 0.9 ohm or close to it .use one that is on the car with the closest value . bosch makes a coil 00012 [ super blue ]that i would use [ easier to find ]
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post #19 of 25 (permalink) Old 04-08-2014, 12:17 PM
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Originally Posted by agillot View Post
first , put pointes back in , use a condenser num 000 156 81 01 , coil num 000 158 49 03 , a 000 158 08 45 ballast , 0.9 ohm or close to it .use one that is on the car with the closest value . bosch makes a coil 00012 [ super blue ]that i would use [ easier to find ]

To setup as old-style/non-transistorized points???

If that's what he's going for, I could provide the details of how mine was wired. It ran, but not well.


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post #20 of 25 (permalink) Old 04-11-2014, 01:39 PM Thread Starter
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As per Luna's advice I pulled the coil to dizzy wire and tried it in a different car which started right up. So I can say pretty accurately that the Hotspark is in fact not working. I have sent another email for an exchange under warranty but the first was ignored (it's been weeks). The alternate condenser/coil/resistor is starting to sound like the way to go. Does anyone know if the transistorized ignition was a smog device? Did the European spec cars have it?
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