Engine shut down at idle 99 C280
 

I have a 99 C280 that cuts off intermittently and unexpectetly at the stop light when in Drive. Sometimes it will start up again and sometimes it won't start until the next day. I replaced the Air Mass Sensor with no effect. There's no OVP in the 99 models. Engine works fine otherwise even at speeds close to red line. When I try to rev up the engine in Park, it starts sputtering at about 4500 RPM but I'm not sure if this is normal at park. Can anyone suggest what I need to do? Thanks.

I know that I fixed an identical issue to yours on a chevy cavalier by replacing the spark plugs.... it was sputtering and idling poorly (and stalling occassionally) with the new plugs it idles smoooth and has better power. The old plugs were charred and shot.

If your plugs are old it might be worth a try. Could also be the distributor, spark cables, or the rotor/coil.

For your first problem ( stalling ), sound like the CPS = Crankshaft Position Sensor.
For your 2 nd " Problem ", it's not a problem!
It's meant to do that.
Not much point gunning an engine above 4 k rpm in park or neutral. ;)

Before throwing an air mass meter at it, did you read the fuel trim adaptation values? Are there any codes?

For some reason CPS doesn't throw codes, so if you're getting stalling and there are no codes or out-of-whack adaptation values, that is the most likely culprit.

Oh, and don't rev the crap out of unloaded engine. That's why MB put a neutral rev limiter in there, but you still shouldn't be doing that.

I first thought that it may be the Air Mass sensor because I was getting a P0110 reading which is the "Air Mass circuit malfunction". I replaced the AM Sensor hoping that it would fix the problem but it didn't but the fault code went away. Now I'm thinking that it may be the crankshaft position sensor but have no idea how to find it and if it has to be programmed by the dealer as some others suggested. I'll appreciate any input from anyone with first hand knowledge. Thanks.

Cps
 

OK I found the Crankcase Position Sensor, and I think I can replace it myself. My last question is: Will the CPS require any kind or resetting or reinitiation by the dealer or will it be good to go after I'm done?
Thanks.

Just install it and you're good to go. ;)

And the hardest part about changing the CPS is finding it. You can locate it by touch, but it's hard to see because it's between the engine and the firewall.

When you put your wrench on it, it takes about 10 minutes to remove it and put the new one on.