83 126 w/ inline 6
 

Just bought this 2 months ago, owned an 79 300D, so this is my first experience with a gasoline Benz.

After driving for about 4 weeks, and having some repairs done to get it through emissions testing, the engine started missing. The car had been sitting for about 18 months with occassional startups to keep everything going. The plugs were old and the air filter was bad, so I took it for a tuneup and oil change / lube. Pricey enough, but it did not cure the missing on 2 cylinders. I took it back to the mechanic, told him I was not happy with the results and he tinkered a bit, gave me a set of used spark plug wires off an old vehicle, tested that the wires were passing current and said he would think about what is causing problem. It runs like a pig, no power at all, lousy gas milage.

He seems honest and is recommended on this site for mechanics. He now says it is just a process of elimination to find the problem, could be catalytic converter, manifold vacuum, or fuel distributor. (Then he told me that a fuel distributor runs about $2600 new and that the used one he had would be much less. I looked them up online and found a new one that appeared to be the right one for $450, kind of hurts his credibility) I have run gas treatment through it twice and am not going to go the route of having a mechanic try one thing then another then another, my experience has taught me that is a quick way to lose a few thousand dollars.

Any one got any DIY suggestions? I am ok working on cars, but am unfamiliar with this one and need a lot of direction.

From your description, the car sound like a 280SE Gray Market car with the M110 engine.

Roscoe, it's odd that the tech would install a used set of ignition wires rather than a new set. The used set may very well be causing more problems than they solved. Ask around to see it there's a more knowledgeable local tech trained to work on MB automobiles. Your experience with the first tech smacks of someone who has poor diagnostic skills.

it actually was described as a 380 w/ a 280 engine, special ordered that way. the guy i bought it from was less knowledgeable than i and was not sure, just said it was a special order. he said that the original owner wanted a 380, but with the 6 rather than the 8. but isn't that what a 280 is?

anyway, it is running poorly and just looking for help in what to check without spending big bucks. i am becoming disillusioned, should have gotten a toyota... ha, don't really believe that one.

What did this "tune-up" entail? Plugs*? Cap? Rotor? Ign.Timing? Fuel filter? (the wires could be fine - test them at night, with a spraybottle of water...spray it on the wires w/ engine running...if you see sparks/arcs you need to replace)

*what kind of plugs? resistor/non-resistor? platinum?

Why dontcha pull each plug one at a time, and see what it looks like - take a pic and post if you have to.

Lotsa questions, I know, but how else to diagnose a car unseen and unheard? :)

thanks for the reply, been real busy, will get back tomorrow, haven't tried the water trick, will do it...

There was a lot of vanity rebadging in the 80's and 90's. A 126 is a 126 and there is little difference between a 380 and or a 280 other than the drive trains. I would check the title and see what the car is registered as. Although the gray market brought a lot of unusual cars. I have seen 126's with the 2.8L engine and manual transmissions. My 300SD has original and quite unusual European lamps when the diesel 126's were US only vehicles. You may never know. Which in some ways is the fun part :)

As for your Toyota comment. Toyota's are great cars but the Japanese have a different philosophy than the Germans. The Germans build a car to last forever where the Japanese build a car to be trouble free and to die a lonely death at about 200K miles. The Japanese turn their backs on their cars after 10 years for parts where the Germans still make parts for most Post WWII Cars. So you have to ask yourself. Do you like shopping for a new car every 5 years or so? :)