Intake Starting Valve

[n/a]

What's the best way to check out the Intake Starting Valve ? I suspect this part to be the one that makes my engine running to rich. I cant get the Co2 under 8.
Thanks for your reply.
Leo

[George Davis]

Leo,

remove the 8 mm screw in the side of the valve.  Then turn on the ignition (don't start the engine) so the fuel pump operates.  Now check the screw hole.  If fuel is coming out the hole, the valve is leaking.  You might want to put rags under and over the valve in case it leaks a lot.

George Davis
'69 280 SL Euro manual

[DavidBrough]

Hi Leo,

If it does leak i.e. more than 3 drops per minute, be very careful when you clean the valve and try to use no more than fine polishing compound if it needs re-seating. I had this problem recently and ruined my CSV by using valve grinding paste and had to source a second hand one as they are very very expensive new.

Good Luck


David Brough
1969 280SL

[n/a]

Thanks David and George,

I did remove the screw, ignation on: no trace of fuel. I removed the valve, connected it and it did work...so....end of suspicion: this
part is defenitly not the cause of the high Co2 and the black exaust-
pipes. Could you give me another hint ? The fuel-pump can't be it:
it is brandnew and sealed. The rebuilded engine did run about 1000
miles without any problem: now it is, some way, drawning in fuel.
Thanks for your interest !
Leo

[DavidBrough]

Hi Leo,

You may find it helpful to search on “starting aid tour” which will take you to Joe Alexander’s helpful thread on how the injection pump enriches the mixture at start up. Whilst you have eliminated the CSV, if one of the other devices is stuck or not working properly that could be the cause of your problem.

Good Luck


David Brough
1969 280SL