As part of the overhaul of the fuel injection system I removed the CSV to check its functionality and to clean it up in our Lab’s ultrasonic cleaner.
On dismantling and cleaning all seemed well, with the needle valve seating nicely and the jets clear. However on reassembly, I could not get the fuel valve to open in response to the activating the solenoid. Something was odd. I then measured the distance from the solenoid’s mounting plate to the needle valve and found that the solenoid’s shaft length was about 5.5mm short of the distance needed to open value! Someone had installed the wrong solenoid, even though it looked exactly right and fitted perfectly.
The CSV solenoid for our cars should be the Bosch 0 330 106 001, has a shaft length of 15.2mm and is outrageously expensive, for what it is.
However, my car had been fitted with the Bosch 0 330 106 004 solenoid from the early Porsche 911, which looks identical, costs around ¼ of the price of the ones we need, but has a shaft around 5.5mm too short.
So if you have persistently poor cold starting but everything checks out, might be worth looking at the numbers stamped on the CSV solenoid to make sure yours is the correct one.
Good luck
Jeff