I have searched the site and found a number of suggestions regarding the potential cause of the hard starting issues I am encountering with my 1989 300E.

The plugs and distributor cap and rotor have been changed.
The wires have been tested and are not arcing
The cold start injector valve has been inspected and confirmed operational
The OVP fuse has been inspected and is fine

After taking it to a second mechanic, he has indicated that it is a fuel related problem and has suggested that we test the fuel pressure in the system. He indicated that he suspects that there may be a leak in either the fuel injectors or fuel regulator valves near the fuel pump.

Would anyone be able to confirm whether this is a viable conclusion.

Another well respected mechanic I spoke to indicated that he would hook it up to a diagnostic machine (ALLEN) and attempt to diagnose the situation that way.

Which would be a better alternative? Any insight would be appreciated.

Thank you