PeachParts Mercedes-Benz Forum - View Single Post

ubertino · #1 10-20-2010, 06:58 PM

I've searched this pretty well, and not found anything quite like what I'm experiencing.

I've got new glow plugs, the valves are in adjustment (just done) and I've also run a diesel purge, replacing both fuel filters at the same time.

When starting the car (in cold mornings) I cycle the plugs once. Car starts right up, within 3-4 seconds, and runs very smoothly for about 2 seconds, no smoke, no problems. And then, it coughs, the idle drops from 750 to close to 500, belching out grey/blue smoke the entire time, and then stalling. The colder the morning, the faster the stall. If I give it some throttle, just enough to get it around 900 rpm or so, it runs rough, kicks out lots of smoke, and in general hates the world.

But, when the engine is warm, regardless of the external temperature, it runs great. Good power, starts immediately when warm, with or without glow plugs. When it's warm there's only smoke if I open the throttle all the way at highway speeds, and I can only see it at night with the headlights of the cars behind me.

I'm thinking that I might have an injector going bad, so the fuel isn't atomizing properly when it's cold, and going out the tailpipe. When it's warm, even though it's not atomizing properly, it's combusting better because of the heat, so it's not noticeable. Unless it's an injection pump issue, or I really cocked up one of the valves when I adjusted them, and that clearance difference is only a problem with startup. Since I got the car in April, it has always run poor during cold starts, but improved to a normal idle very quickly, in far less then a minute. As the cold has increased, so has the stalling, but I also adjusted the valves around the same time too.

All of that said, if it is the injectors, should I get those bosio nozzles that people talk about, or take mine for a rebuild? I've got, hopefully, 150k on them. Unless the car has a newer odometer, which is always a chance on these cars.