listening to injectors

[GRUMPYNOMO]

That was a good tip offered to quickly find an isolated/faulty injector by
listening with a stethoscope.  I can add that the stethoscope should be a
solid rod mechanics type (not a hollow medical type).  It is important to
identify an identical position that can be reached on each of the injectors.
The position should be as near to the pintle as possible.  
While practicing, listen also to the fuel rail and the induction manifold near
to the injectors.  It can become confusing when you find that the click you
think is the injector sounds pretty much the same anywhere on the fuel rail
(Jaguar and Range Rover experience).  best approach I know is a sensitive
current probe on a Fluke 98. Volts show the ECU is working, Amps show how the
injector is using it.
Bottom line, though, is we often listen first to zero in on a problem area and
then get the electronics out.