1971 350 SL Electronic injection. Wet spark plugs

I have a 350 SL 1971 with electronic injection.
The engine vill not start. The spark plugs are very wet of gasoline so it will not ignite. If I block the fuel hose from the fuel pump with a vice grip. Take the spark plugs out and run the engines so the gas blow out of the sylinders. Put on dry sparkplugs.
The engines start and goes in 2 -3 second . If I open the vicegrip, and try to start again, it will not start. Spark plugs are wet. Someone know from experience what's wrong ?

[Greg in Oz]

Fuel mixture is way too rich. Some possible causes are:
1. Faulty fuel pressure regulator causing fuel rail to run at excess pressure (should be about 2 Bar or 30 PSI). A check of fuel rail pressure would verify this.
2. Faulty cold start injector constantly injecting fuel. Remove cold start injector and switch on ignition (do not start) to see if injector is leaking fuel.
3. Faulty coolant temperature sensor. Measure resistance value and confirm that this agrees with values stated in workshop manual.
4. Faulty manifold pressure sensor. Difficult to test other than by sustitution.
5. Faulty ECU. Difficult to test. One possible test is to listen for injectors "clicking" while the engine runs. This is difficult in your case since you can only get engine to run for a short time. With ignition on but engine not started, you should hear the injectors "click" as the throttle is slowly opened.

Hi Greg.
My mecanic have found the problem.
The fuel electronic control unit put out a injection valve time 140ms. Normal time are 4 ms. I need a new control unit, or a good used one
Have a happy new year from Norway
Arvid