Ignition wires!
 

How do you get them off the old cap without damaging them, or do you just toss the wires and replace? I bought plugs, cap and rotor as the car is new to me and I have no record of their replacement. Car runs ok except for a brief stumble on start that goes away immediately.

Also, the black cap-shaped cover is cracked, can I just glue it?

'91 300SEL

the black cap inner cover is only about 16 dollars... the top cap is about 7.

you just have to be patient and wiggle and pull the wires off of the cap.... it seems like the will never come..but then one by one they do..

put so dielectric grease on them when you attach them to the distributor cap again.

give the wires a twist before pulling as to break the seal the rubber boot has on the tower. The top cap is just a weather cover so it could be glued.

Thanks guys! Tomorrow, I will tear into it!

I figured out how to get the wires off, with your help thank you.

How do you get the bottom bolt loose to remove the cap? Do you have to take out the fan and shroud first? Must have been designed on a Friday afternoon, or early Monday morning. Obviously designed to make Mercedes mechanics rich!:vbac47679

Xsbank, it makes things easier to remove the shroud. No need to remove the fan ... use an allen wrench positioned between the fan blades. Note the terminals on the Bosch distributor cap are marked with the corresponding cylinder numbers which are 1 thru 6, front to back. Remember to apply a light coat of dielectic grease to the inside of the spark plug boots before reinstalling so they come off easier next time.

I have used a standard allen wrench to break the bolt loose.... then i have an 3/8 inch allen socket set... i attach an extension to the allen socket and turn the bolt loose by hand..

no removal of fan or shroud in my case

Thank you, gentlemen!

Ok, went out and bought a new set of allen keys and managed to replace the cap and rotor, ran out of daylight, so plugs tomorrow. I thought it was running really well but took it out for an Italian tune-up right away, it now runs like a turbine, 'seems' to have more power (I won't be frightening any old ladies, but its better). The cover over the cap was not reuseable, old, dried-up and cracked so I'll get another one of those on Monday as I assembled all of it with dielectric grease so it should all just pop off again.

The secret with these cars seems to be to not be afraid to attack them with wrenches, just get to it. I was a little intimidated, but its just a car, even though some of it looks like it was designed by British Leyland or Alfa Romeo.

There's an amazing amount of crappy plastic and too much German rubber (that smell that old BMWs and VWs have) but it looks to be closer to a Volvo than a VW, and every improvement is VERY satisfying.

Having said all that, I will be back to this well to dip it for more information, soon. Thanks everyone!

Xsbank, be sure to use Bosch F8DC4 sparkplugs.

I checked the ones sent to me and they are Bosch HR9DC. Does that mean they sent me RESISTOR plugs? ^%$&^%# and $%#@^%$!!! AArrgghhh!!!

Xsbank, yes ... the HR9DCO are resistor plugs; however, I don't think Bosch makes the H9DCO plugs any longer. Check with your local MB dealer that the F8DC4 plugs are OK for the 103 engine. A tech at our local MB dealer told me years ago that all the 124 engines run better with the F8DC4 plugs.

i recently got the H9DCO plug at my dealer... it was about 3.32

Went to the dealer, resistors only! Went to the auto shop, resistors only there, too.

What about using resisitor plugs and just getting new racing-style wires with the shielding and no resiitors built in? I have no idea what they cost but obviously plugs will be a problem from now on, so some permanent solution is necessary. I'll do some research and let you know.

Without going into the long drawn out explaination that has been hit on multiple times in this forum, do a search, you need to use MB type plug wires and non resistor plugsw to get the best running most efficiently running engine. Long explaination but seems to be true. I tried it both ways and have since gone back to the proper wires and plugs, even though they are hard to find.