4matic problems

I have a 300td 4matic 1993 350,000 kilometers.Works fine .Sometimes when I start the car from cold the engine missfires for a second,probably because the diesel has dropped back a bit.When this
happens the 4matic warning light comes on and no 4 wheel drive. If I disconnect the battery and allow the computer to settle back to factory default settings and then reconnect and then start the car the fault is gone. The question is can I put a manual swith in the system so that I can switch on the four wheel drive when i need it? And where would the swith go ,has anybody experienced anything like this?This is a wonderful car and Ive never even seen another 300 Turbo diesel Estate,plenty of petrol ones so id like to fix it
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Replace the engine's glow plugs so it doesn't misfire and leave the more complicated 4-matic system alone.
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thanks for coming back so quickly.Ive just done that with six new MB plugs,I thought if Im taking the inlet manifold off I just as well do the six.Its exactly the same.????
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If the motor ALWAYS stumbles after a cold start I'd suggest you check the fuel system's hose connections and fuel filters for tightness. A small air leak into the fuel system could be causing the stumble.
Since you don't mention misfiring upon starting, the existing glow plugs must be working, perhaps not at 100%, but none the less working. So I'd suggest you also consider adding some diesel injector cleaner to the fuel - 1 or 2 cans - to ensure the fuel injectors are clean.
I believe one needs to remove this motor's intake manifold to reach all six glow plugs. If you do this be sure to install either Beru or Bosch glow plugs.
Once the engine's stumble is cured, further problems with the 4-matic, if any, will be only related to that system.
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I use the cheap chinee Monarch plugs. They don't last as long, but they burn hotter; I recommend them for older engines. I change them once a year in the fall. It makes a HUGE difference IMO.
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supergun wrote:

I remember the German w124 buying guide mentioned staying away from the 4matic models, and from the 200 carburettor model as well. I got burned ignoring that last advice... ;)
Ximinez
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The Spanish Inquisition wrote:

This is the 'Kaufberatung' I was talking about. In German, alas:
http://w124-club.de/dss/Kaufberatung.pdf
Ximinez
--
Our three weapons are fear, surprise, and ruthless efficiency...
and an almost fanatical devotion to the Pope....
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