Frank,

I did lean out the mixture but then the engine
will run even worse at the point that it cuts down
And it doesn’t help the startup
But today I try to start my engine cold with CSI disconnected and gaspedal fully pressed down
And it worked like always. But please notice that it always generates a blue/ black smoke
And engine kept on running roughly even when warmed up. Heavy acceleration was bad
Then after a 1h drive, I let the car cool down for 5h
Ambient temperature dropped till 16degree Celsius
I decided to connect the CSI but before starting
I loosened the inlet and outlet fuel connections on my WUR
I waited about 20 min
Then I fastened both connections again
Now I tried to start: car started immediately
And I also did not hear any squealing sound when pump primes before the start

So I am now trying to see whether vacuum is holding my plunger up after cooling down the engine

I will do the same test tomorrow morning

I wanted to share some videos but currently it is not possible on this forum