OK . We can now continue ..
[ If the pump was working at both temps . as your post indicated, we would go into a completley different diagnosis]

When the clutch is engaged by the ECU, there is also a Switchover Valve that is also energized by the same circuit. This SOV allows engine vac to reach the flow valve between the pump and the engine . It is quite common on these 104s to have a broken vac line going to this SOV. It is the white plastic line in front of the engine, under the front cover . Check that and also check the vac line coming out of the SOV and going to the flow valve.
Report your findings.


The code 11 can be if you had lifted the pedal cable from under the hood when working on the car or the cable could be sticking... see if there is a little play in the cable [ there should be 1/4"] .. erase that code for now.