ML320 Runs really Rough Sometimes
 

My MY 2000 has always had a small problem that seems to be getting worse.

When the engine is cold and if I put the engine under a bit of load then it starts to run really rough (no power , won't rev , idles at about 1,00 rpm really roughly).
If I turn off the engine and restart it always fixes itself immediately.

It has done this since new and the dealer has never been able to fix it.

I have had the MAF, CATS, and plugs replaced in the last 2 years and thes ehave not fixed the problem (they were rpelaced for different reasons though).

I assume the computer is getting it's knickers tied in a knot as I assume that by restarting the engine I am resetting the computer ?

Any other ideas ?

thanks

Doug

What you are describing is injector shut-off. That happens when the cylinder misfires badly. When you re-start the engine the misfire counter re-sets.

I would think that you possibly have a bad spark plug wire OR coil..

thanks, - just one more question , would the injector shut off log any error codes ?

I had the codes read last time I had the car serviced and it read faulty O2 sensor right hand side and faulty brake light switch (the BAS and ETS lamps did illuminate once about 6 months ago, but never since).

The dealer suggested not replacing the O2 sensor as he didn't think it would fix the problems I was having.

thanks

Doug