Naj, thanks mate. That pic was actually very helpful to me today. I started the day by trying to flush the cold valve pipe with several liters of fuel. One thing I noticed was that there was still a large amount of sediment in the bottom of the jar after each flush. That amount would really block up the cold start injectors if it got passed the fine mesh filter. I was also still at a point where 8psi would hardly push fuel through the mesh filter even though I had already soaked it for a week and also blown several hundred cubic meter of air through it.
Not knowing what is normal has been my nemesis on the fuel leg of my restoration. There are so many aspect where if any one is wrong then the whole system falls down. Two filter at the rear that could be blocked, the fuel delivery pump not delivering either enough volume or pressure, the main fuel filter potentially being blocked, hoses being kinked, the main fuel hard lines having obstructions, the cold start valve filter being blocked, the cold start valve not sealing, the cold start injectors being blocked. Any one of these could stop the system let alone a combination.
Today I had a combination.
First up I went to work on the csv steel pipes. I decided to use excess pressure and water to blast out any remaining muck. Made up an adapter out of an old injector and another W108 fitting which happened to have exactly the same thread as my 1700psi Kartcher water blaster.
Worked beautifully. Left the pipes constantly blasting for a 20 minute period. Was quite entertaining to see the huge rooster tail coming out of the old Merc pipes. Small minds I guess!
I blew the pipe dry with compressed air and tried it again back in the car and to my delight all the fuel coming out was crystal clear with no sign of any debris.
Still the same problem though. The pressure was barely enough to get the fuel through the fine mesh filter let alone out the injectors. So I decided that I had nothing to loose and pulled the hose back off and blew 1700psi through the filter for 10 minutes. I could tell instantly it had made a huge difference by just blowing through it.
Hooked everything back up in the car and I now have two nicely formed spray patterns with 8psi.
At this point I think it will be good enough to start the car. Certainly a massive improvement over when I took it all apart. I have no idea how it functioned when I got it.
The day was going really well until I went to do a full test. Until this point I had removed the plunger in the csv valve so I didn't need the csv solenoid engaged to squirt fuel. Discovered that my csv is faulty. Desperately need another one in order to start the car. I have a solenoid off a spare 280 csv but discovered that the plunger pin is slightly longer on the 230 variant. I have a working second hand 280sl solenoid if anyone wants to swap for 230 one. I will throw in the whole csv to sweeten the deal!
I guess I have made good progress irrespective of the solenoid. I can now bolt up the csv and move on with the throttle linkage.