Hi Men. At wits end. New coils,Plugs,MAF,MAP,Crank sensor,Pressure regulator, Injectors,Throttle position control. The problem is the number 2 injector cuts out intermittently. When I start the car it fires fine. When put in gear the injector electrical stops firing, Tested injector is fine. I lose electrical voltage to #2 injector. Stop start car it comes back and problem is reapeted. Recently got a new key from Mercedes ignition switch is a little rouge getting key out. At wits end. Could it be ignition switch or wiring harness. It just keeps losing power to that injector! Any sugestions would be greatly appreciated. its a Kompressor. Thanks!

On my 97 SL320 and 97 C280 ( M104 with ME2.1 injection ) if I create a miss fire by shorting a plug or disconnecting the injector wire, the computer sees the miss fire then shuts off the injector to prevent raw fuel from damaging the cat converter. Cycling the key will bring it back online. In your case, something is causing the computer to see a miss fire.

Do a compression test and a leakdown test to make sure # 2 is building enough pressure.

Also look at scan tool miss fire counts for all cylinders.

I previously had a misfire on cyl #3 that is now gone. Compression os ok. When you refer to cycling key do you mean start and stop restart? or just turn key to far position a few times? I will check the coil and plug both new but that means nothing. I appreciate your response. Any thing else you can think of is appreciated! Thanks.

Cleaned EGR replaced wrong gapped spark plus and coil. So far so good. Had this baby for many years runs like new. Lets hope it stays that way. Thanks for your imput!

Turning off the engine, waiting a say 10 seconds for everything to power down then restart. ( You might get away with a shorter cycle but start there )

Per your last post, a large gap can cause the cyl to miss fire. Did you change all the coils during the first round of repairs or just a few? What about the coil to plug boot?

I came across the injector shut down on miss while diagnosing a bad MAF. If the MAF went completely off line, the computer would sub a value and keep the engine running. Sometimes the MAP would go off scale and not let computer go into limp mode, this made for a really odd random miss.