I'm reposting my problem with my 90 300E that would not idle. Now it will not start. The problem is in the Fuel injection system. The car will fire on a small amount of starting fluid and die. The ICV shows zero volts on the harness. Should it show some voltage KOEO?

Some more background. The car use to idle low and rough when started cold. Once warm the idle would be smooth. Yesterday the A/C compressor would not engage. I drove home on the highway with no problem except the A/C not working. When I exited the highway and came to a stop the car died. It would restart if I opened the throttle slightly but it would not idle. Once I got moving the engine ran fine. Come to a stop it died. Today after the engine cooled, I can't get it to start. Can the OVP relay causes this? How can you test the OVP? Thanks for an input.