I have had a misfiring engine upon cold start in morning twice. Both times I restart and the misfire goes away (The second time it took a couple times). I went back out side and started up the car to check codes and there is no code now. Any ideas? I have been seeing a lot about the dual fuel pumps does this sound like symptoms of that?
thanks
2008 MCSm

 

The fuel pump in my 07 MCS is being replaced at the moment. I think the fault code was low pressure in the fuel rail. I should know tomorrow the results of the repair. In any case, it's been requiring several start attempts ever since the temps went below 40F. Push the start button and it stalls right out.

 

I just had the exact same problem. One cold-ish morning out of the blue the car started sounding like crap when i started it in the morning. A CEL came on and went away after a couple restarts.
The car kept sounding kinda awful when starting in the cold, and a couple days later i had a constant CEL for random misfires in 2 cylinders.
Took it to the dealer and they diagnosed a high-pressure fuel pump failure.
After the fixed it the CEL is gone, but the car still sounded a little dodgy when i picked it up. I just got it back today, so we'll see if it's all sorted.

Forgot to mention that it also started stalling out on me when starting.

 

I started a thread on the same thing recently. I never get a CEL though. I bet it's the same pump.

 

When my high pressure fuel pump went out I didn't initially get the CEL. I had the problem for about 3 weeks before I finally got the warning.