1977 911S with .033 WUR
Symptoms
Cold starts are really hard and irregular. Sometimes the car fires up instantly only to die. After a few tries cranking, starting and dying it will eventually start and idle rough for a minute or two until it settles in. I have to let it sit for a few more mins otherwise the first 5 mins of driving are rough.
I followed Tim's CIS for dummies instructions along with Jim's Basement Workshop as a guide. Had no trouble with the gauge install and tested the gauge against a very precise one I have at work and it's just about spot on accurate.
Results
System Pressure Test:
https://www.youtube.com/watch?v=2Cqcf2sHhSw
This one seems to be right on spec and the pressure is 4.8 bar, right between the 4.5-5.2 range for my car/WUR
Cold Control Pressure Test:
https://youtu.be/UVZ2KVBbo2s
Super confused on this one. It shows just like the other test and not like the ~1 bar it's supposed to.
Warm Control Pressure Test:
https://youtu.be/jcwLx0ui5Z0
Again, super confused about these results. Right back to 4.8 bar and almost no change as the WUR heats up. In addition loss of pressure is almost instant and not like it's supposed to
No signs of fuel leaks, no smell of fuel once the fuel pump is off.
The car was at my mechanic for some work and they claimed they fixed the starting issue but apparently not. Could they have tinkered with the WUR and thrown it out of spec?
I have a smoke machine and I'll perform that test next to check for unmetered air and vacuum leaks.