[T_MaX]

On CIS, the cold start injector is not the item you need to look at.

MB calls theirs a Warm-Up Regulator (WUR); I'll have to look at the Porsche docs to see what they call it, I’m sure it’s the same. The WUR acts as both a Fuel Regulator (used during idle), and as a Warm-Up Regulator.

The point is, during warm-up, the WUR bumps up the fuel pressure just little more than normal. When it goes out of spec, it bumps the fuel pressure up either too much or for too long, as it is always better to run rich, than lean.

The WUR is controlled by vacuum and a heated bi-metal strip inside the WUR. So you would need to check too make sure you’re getting the correct voltage and vacuum to the WUR.

In order to check the WUR itself, you will need a fuel pressure gauge and fittings to tap into the fuel line that runs to the fuel distributor.

P.S. These are just a few things I can remember off the top of my head, I suggest looking at the FWSM for specs and procedures.