I have a 1997 E320 with 110000 miles, I just changed the fuel pressure regulator because it had an internal leak also replaced the battery it was already about 4 years old, so after doing all that went to start the car and it would crank but no start,check the spark plugs for juice and they were ok so I figured that I might as well change the cam and crankshaft sensor since I have that many miles, did that and no start, next I did an ohmm check on all the injectors and they ohmmed out at 14.2 sao I did a manual injector triggering and they all worked so I check for the electrical impulse to the injectors with a noid light and bingo no electrical impulse to the injectors, so now I'm kind of lost because as far as know I'm at a dead end, can somebody help?

I don't have a wiring diagram for the E320, but on my VW the positive to the injectors runs through a fuse which is fed from the ignition switch. The ECM triggers the injector by completing the circuit to ground. When you manually triggered them, did you use the positive lead in the connector to the injectors with your ignition switch on? Or check to see if you have 12V on the positive lead in the connector. That would verify the positive and any fuses in the circuit. Otherwise, if you haven't already check your fuses. Other than a bad ECM, I don't believe there is any other individual component that would stop the ECU from triggering the injectors especially if you have spark when cranking.

Sounds like a "Drive Authorization" issue.
Stop spending money and try another key first.

It does not have an electronic key.

Regular key