Fast idle and sluggish at first
 

I'm having a couple of issues that may be connected. 89 - 300e M103, Cal car - ck engine light on - when pressing the button the diagnostic connection it will blink back four, and the only thing I've found on codes shows only four codes 1-OK 2-Speed sensor 3- Coolant temp sensor, and 4-ELR control unit or idle speed control system. I assume this means the valve. The idle speed is 1000 when cold and the 1500 when warm. I've been told that when the idle speed control valve fails, 1500 is where it goes to, but I hate to just through parts at it. So 1- is there a way to test the valve or is the code four the tell?

The other issue that may be related to the first is that when cold the system seems like it's loaded up and has no power. I can tend to overcome this by forcing shifts at about 3000 and in a very short time everything runs perfectly - or seems so. The Bentley book kind of points to this and recommends adjusting the fuel distributor's lower pressure up to 6.5psi from 4.8psi, and then adjust the idle mixture. Doing this before replacing the valve or both at once? Where is the port to read the lower pressure from, and how is the idle mixture adjusted?
Thanks

Anybody? Or point me to another thread

Code 4 is "air flow meter position indicator" which sounds a bit like a bad potentiometer on your air flow meter. The good news is the potentiometer is replaceable on your car, the bad news is that is apparently no longer available from Bosch as a separate part. Try a search for "potentiometer" - quite a bit has been written on the subject.

Thanks - found the codes - there are only 12 in the list - correct?

I really need to know where to read the LP fuel pressure for the EHA?

Anybody - please, and has anybody done this? Q1 at the top. Then why would the idle mixture change?