Classic Mercedes tune up

Just a thread to document the hassles of basic maintenance and tune-up of late 80's mid 90's Mercedes. My DD is a W126, big boxy S class. Rebuilt the entire engine at 200k due to a failed head gasket and have since driven 15k. Time for plugs and other items.

Here's the PITA problem, spark plugs... seems easy enough right? HA! Apparently Bosch and everyone else decide that the US market for non-resistor plugs was no longer viable. Bosch no longer mfg's them. What's the big deal you may ask? well the plug wires already have a resistor core, adding R type plugs will cause all kinds of crappy problems. Took some digging and found that Denso still has some available and ordered a bunch from a local warehouse.

Mercedes w/Bosch designed the ignition system to run nickle core non-resistor plugs exclusivly, any other type of plug will not work correctly. Hard starting, stumble, misfire, etc..

One day I may have to just break down and strip out the CIS-Kjet E and drop in EFI and COP ignition.

Who'd thought that German car parts would go obsolete this quickly!

 

Not sure.... if sarcasm.... or not?

Or your mechanic had a strange way of explaining what happened. A crankshaft sensor simply 'reads' the crankshaft position so that the ECU or computer knows when to fire the injectors and ignition, think of it as 'fancy points' without it, the engine will not run.

Now Mercedes did place them in some very odd places in the mid 2000's like right above the exhaust manifold... gets' cooked in that spot.

I get a kick out of the fuel line running thru a chilled A/C line in the engine bay to keep the fuel from vapor locking, another reason why the A/C is on all the time.