1971 280SE Points Fry
 

Hey guys,

Wish I would have found this site years ago... I'd been that much further along - these posts/information are fantastic! My questions are rather basic, so please forgive me. I've been researching this site... looking for a similar situation... but; after my recent discovery... I need some help to figure this out.

Two issues; the first is 'fried' points. My 'basket-benz', M130, 108 has what is defined in the shop manual as a 'standard' distributer installed; i.e. not the distributor matched for the transistorized coil. The disty also has a condensor attached. (I've reviewed your posts saying that should be the first to go!)

However - I have a transistorized coil and a ballast and what appears to be a second resistor close to the coil - but no switch box.

The shop manual says .3mm on the initial points gap for the disty I have. But for the transistorized coil and resistors... .4mm (the reason for the points fry?) The shop manual is showing a switch box with the blue coil; can't locate the described switch box.

Big problem... it fries the points. Not right away... after a period of a couple of months... they become 'fused' and I'm stranded. I am seriously considering going to the Pertronix or Crane/NGK's - should simplify my life greatly. But in the interim? Any thoughts and/or suggestions would be most appreciated on what settings I should use. I thought perhaps .4mm and set the dwell for the transistorized coil... but no switch box is baffling me.

My next question is most probably a clarification; the Benz is pretty low in the front end once I had the rear compensating spring installed. Should HD Bilsteins remedy this?

Thanks for any help you can offer!

GAR
'71 280SE

What's the point?
 

You have a bad ballast resistor before the coil or a bad condenser in the distributor.

Go ahead and change to either the Pertronics or the Crane. You will be much happier. The original electronics were fine 20 years ago but heat and constant use takes their toll.

The Switchgear box is under the battery tray.
The cond. on trans ignition [scond generation] is RF only and a bad one will cause point burning. It can be disconnected..
On the front suspension, check the subframe mounts for collapse/deterioration

Do the pertronix, I have a set in my 404 unimog (m130 conversion) runs great, I've never had ANY ignition problems.

As for the low front end... shocks really shouldnt really help, they'll just make it ride stiffer. If you haven't replaced your subframe mounts, or know that they have been replaced in the recent past they are more than likely shot, which would result in a low front end.

Another possible culprit - the distributor ground 'pigtail' wire that's either black/white striped or green, it runs from the distributor to the negative ground terminal on the standard bosch coil. That piddling little wire can corrode and crack at the connections over millions of years. It's the kinda thing that nobody checks, but can effect current flow through the points. Smart move might be to trim the distributor pigtail ground wire 1/2" at the end and reset the connection over a fresh bundle of copper wiring, sometimes they end up hanging by a thread.

Must have a dwell tach instrument ($9 on ebay?) to set the point gap too. Feeler guage at .3 mm is just ballpark figure. Forgotten how to hook-up a dwell tach, but somebody here can talk you through it.

(edit: and replacement coil springs for all four corners are surprising cheap considering itsa once in car's lifetime thing to do, somewhere around $150 each i understand.

Guys,

Thanks for all the great info... you saved me a great deal of time/effort!

I will check out/disconnect the capacitor and install the pertronix sometime
soon as well as the subframe mounts/coils sprgs. Yeah - been "awhile" since I've done dwell; might check back into you guys for more advice on that or other things I run into trying to get this beasty road worthy once again.

I really appreciate the help! Thanks again.

Cheers

GAR
1971 280SE