Symptoms of a failing Ignition Control Module? - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 03-19-2013, 09:54 PM Thread Starter
BenzWorld Member
 
Luna Gaudi's 72 250's Avatar
 
Date registered: Sep 2012
Vehicle: 1972 Mercedes Benz 250
Location: Santa Fe, NM U.S.A.
Posts: 389
Mentioned: 0 Post(s)
Quoted: 17 Post(s)
(Thread Starter)
Symptoms of a failing Ignition Control Module?

What are the symptoms of a failing control module? Is it possible for it to work and then not work and then work again? The car started right up, and as I slowly pulled out onto the road from my driveway I hit the accelerator and the car pulled hard as usual then almost immediately the car died. I tried to restart and nothing. Luckliy, I was only about fifty feet from my drive way and a friend help me push it back. First thing that I checked for was spark. There was nothing at the plugs or coming out of the coil. I assumed it might have been the coil so I orderded one up because this the one that is on the car is the original 40 year old coil. Today, I had a chance to pull out the trusty meter and started to diagnose the problem. With the ignition on, I seperated the contact on the points and checked for any voltage reading from ground to the positive wire on the coil, there was nothing.(per Haynes book) I checked the ignition switch to see if everything was plugged in tight, it was. Checked for continutiy on the resistors, they were fine. So I decided to pull out the control module, everying was plugged in tight. I removed the screws from the back of the moduel and peaked inside. Although everything in there was covered with a redish brown "sealer" nothing looked like it had burned out. I put the cover back on and hooked it back into the car. With the ignition on, I checked with my meter again, one lead on ground and the other to the positive wire on the coil and now, it's showing power. I got back in the car and it started right up! Any thoughts or suggestions? My friend that was helping me had accidently dropped the module on the ground, that couldnt have got it back to working order? could it? Isn't it all solid state? What are the symptoms of a failing ignition module?
Luna Gaudi's 72 250 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 03-20-2013, 06:00 PM
KCM
BenzWorld Senior Member
 
Date registered: Jun 2004
Posts: 499
Mentioned: 0 Post(s)
Quoted: 17 Post(s)
When it comes to electronic iginition modules, they can fail and have various symptoms ranging from intermittent operation to completely dead. I'll share my experience with my 560SL. My car would normally start and run well. Once in a while after shutting the car off after drving a while (engine warmed up) and then trying to restart, it would not start. After sitting for 20 or 30 minutes the car would start right up and run good. This symptom is common with electronic modules and ignition coils where something inside shorts out after the unit heats up either from being on or from heat absorbed from the engine. After a while my car failed to start even with the engine cold (no spark), then out of the blue there was spark and it started and ran fine again. I changed the coil (thinking it was shorting out when hot) and the ignition pickup to no avail. Finally changed out the ignition module for another used one and have had no problems since. It was definitely the module failing intermittently.

Not sure how your coil is wired, but if it is similar to my 560SL where it gets power through the module, then I'd say the module could definitely be the culprit. Maybe a loose terminal or solder point that again made contact when dropped.
KCM is offline  
post #3 of 11 (permalink) Old 03-20-2013, 10:21 PM Thread Starter
BenzWorld Member
 
Luna Gaudi's 72 250's Avatar
 
Date registered: Sep 2012
Vehicle: 1972 Mercedes Benz 250
Location: Santa Fe, NM U.S.A.
Posts: 389
Mentioned: 0 Post(s)
Quoted: 17 Post(s)
(Thread Starter)
Thanks for the input. I am heading to the old boneyard to see if I can pull one off of the 280 thats sitting in there. I figure I might keep an extra modual in the trunk and just in case, be able to swap it out on the side of the road in about twenty minutes. I really don't want to spend $ 1,400.00 for an oem modual.
Luna Gaudi's 72 250 is offline  
post #4 of 11 (permalink) Old 03-22-2013, 08:55 AM
Premium Member
 
Date registered: Nov 2012
Posts: 1,241
Mentioned: 0 Post(s)
Quoted: 59 Post(s)
Premium Member
remove module , replace coil with a standart ignition coil , install a condensor at the coil minus [ going to pointes ] ground body of condensor with a wire / hose clamp . you will have to modifie wirring to coil , ignition to plus of coil , and minus to pointes . coil num 000 158 49 03 , condensor 000 156 81 01 .and a ballast 000 158 08 45 [ 0.9 ohm ] or use one that you have on car , close to that value . you could also use a us car set up , coil , condensor / ballast out of a 60 s car .
agillot is offline  
post #5 of 11 (permalink) Old 03-22-2013, 12:42 PM
Lifetime Premium Member
 
Date registered: Dec 2004
Vehicle: 1972 280CE
Location: Dallas, TX
Posts: 3,888
Mentioned: 1 Post(s)
Quoted: 108 Post(s)
Lifetime Premium Member
Yes, they can fail intermittently. Also check your points.

With best regards

Al

Check out the W114, W115 /8 enthusiast forum http://www.stroke8.org

My 280SL restoration
alabbasi is offline  
post #6 of 11 (permalink) Old 03-23-2013, 08:09 PM
BenzWorld Extremist
 
Date registered: Sep 2012
Vehicle: 300sel W109, 280S 70 , 220s 62. 230 66. Lancia Flavia 63.Pininfarina
Location: Totteridge London.
Posts: 807
Mentioned: 0 Post(s)
Quoted: 59 Post(s)
[QUOTE=Luna Gaudi's 72....swap it out on the side of the road in about twenty minutes. I really don't want to spend $ 1,400.00 for an oem modual.[/QUOTE]

Alternately an excellent replacement would be a pertronix electronic unit ,fits under the cap and works very well all for under $100.
15 years on my car with flawless performance .
adler is offline  
post #7 of 11 (permalink) Old 03-24-2013, 12:13 PM Thread Starter
BenzWorld Member
 
Luna Gaudi's 72 250's Avatar
 
Date registered: Sep 2012
Vehicle: 1972 Mercedes Benz 250
Location: Santa Fe, NM U.S.A.
Posts: 389
Mentioned: 0 Post(s)
Quoted: 17 Post(s)
(Thread Starter)
Quote:
Originally Posted by adler View Post
Alternately an excellent replacement would be a pertronix electronic unit ,fits under the cap and works very well all for under $100.
15 years on my car with flawless performance .
Adler, I think you might be right here. I probably should upgrade to the pertronix unit. Could you give me some more info on where to buy and any tricks or hints to install. It will be on a 1972 250. The engine was replaced with another about 12 years ago. I'm not too sure if the replacement engine was the same as the stock one. On the engine that is currently in the car, the drivers side of the block is stamped "280S / A". Is that a 2.8 liter and will that effect the type of pertronix unit that I should buy?
Luna Gaudi's 72 250 is offline  
post #8 of 11 (permalink) Old 03-25-2013, 10:18 AM
BenzWorld Extremist
 
Date registered: Sep 2012
Vehicle: 300sel W109, 280S 70 , 220s 62. 230 66. Lancia Flavia 63.Pininfarina
Location: Totteridge London.
Posts: 807
Mentioned: 0 Post(s)
Quoted: 59 Post(s)
okay that is a M130 engine .The kit installation is simple and easy with the instructions provided.
i got all my kits from 'retrorockets ' but there are quite a few other ones if you google pertronix kit.
aAd
adler is offline  
post #9 of 11 (permalink) Old 03-25-2013, 03:40 PM
BenzWorld Senior Member
 
drew56cus's Avatar
 
Date registered: Oct 2006
Vehicle: 1965 220SE sedan (finnie) with 450SE conversion, 1964 220SE coupe project, 1966 300SE coupe
Location: Brisbane Australia
Posts: 418
Mentioned: 1 Post(s)
Quoted: 32 Post(s)
You should really look on the distributor itself for a little metal ID tag that has a number on it, as this is what is important when ordering a pertronix. ponderosamustang on ebay sells them too. Have a look on the engine for stamped numbers (not cast) that start with 130 - that will be the engine number.
Cheers,
Drew
drew56cus is offline  
post #10 of 11 (permalink) Old 04-01-2013, 01:36 PM Thread Starter
BenzWorld Member
 
Luna Gaudi's 72 250's Avatar
 
Date registered: Sep 2012
Vehicle: 1972 Mercedes Benz 250
Location: Santa Fe, NM U.S.A.
Posts: 389
Mentioned: 0 Post(s)
Quoted: 17 Post(s)
(Thread Starter)
I couldn't really find a metal ID tag. It only looks like a part number, could this help me to buy the correct Pertronix?

0 231 187 002
JFU 6
Attached Thumbnails
Click image for larger version

Name:	DSC02696.jpg
Views:	237
Size:	42.3 KB
ID:	506174  
Luna Gaudi's 72 250 is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome