560 Cold Start Problem Griped But How To Solve?
 

Finally I found the causing of cold starting problem in my 560SEL 1989. After more that a week of tests I found the there is no electricity to the cold start valve (the 9th injector). Wiring is ok, where shall I start?

Hello,

The way I understand it the cold start valve only gets current for a very brief period of time at start up (seconds). Did you check for current while someone else was starting the car?

Otherwise you shouldn't find current at the cold start valve, unless I'm really off base.

Yes, that's exactly what I did when the car was cold. So mainly, from where it will take the current?

560 Cold start
 

Exactly how cold was the engine when you tested it?
The cold start valve will not open at temperatures above +15c (59f).
Check the two pole temp sensor on the manifold, Resisatnce should be nearly the same measured from ground to each pin seperatly. At 20c the resistance should be 2400 to 2600 ohms.
Good luck Mike

Well I guess it wasn't less than 20c. Thus it didn't function....
I'll try to change the fuel relay and see..

True, the cold start valve will not operate at temp (water temp, not air temp) above 15c.