My 1986 300E has a cold start problem like many I've read about in this forum. First start in the morning (or after it sits a few hours) is difficult. I can start it only by holding my foot down on the accelerator pedal while cranking. It catches pretty quickly, then I have to carefully keep the RPMs at 1000-1500 for about 15 seconds and it will then hold a low idle while it warms up. The idle speed when warm is about 700, 600 in Drive. Power seems okay.

At this point, I'm ready to buy and replace the EHA. Every thing else I find seems to be okay:
* the dual engine temperature sensor (rear of engine) has the correct resisatnce on both legs and the wiring is fine to both computers.
* the OVP relay and fuse are fine (replaced a year ago)
* voltage is getting to the cold start valve
* idle control actuator resistance is 8 ohms (seems reasonable) and it is getting voltage to it.
* repaced the plugs, wires, cap and rotor a few months ago.
* All of the vacuum and air hoses seem intact and I am getting pretty good vacuum.

Anything else I should try before I get an EHA on eBay? (And is a used one a reasonable risk?)

Thanks.
Brent Smith
1986 300E 273k miles