2000 A8: No signal from crank sensor
 

Installed new crank sensor and same problem as before: will not run.
Before new crank sensor: no combustion in any cylinder. After installing new crank sensor: One cylinder will fire. Tried starting fluid, still only one cylinder fires.
Checked fuses, good.
Crank sensor connector under the hood: wires from it go into a big wiring harness toward computer under right side of hood.
At this point I do not have test equipment to solve this problem.