Disco 2 TD5 rev counter on starting

Never noticed but had trouble starting and noticed no RPM on rev counter, checked under bonnet and , injector loom is a bit oily (got a replacement), tried starting with Hawkeye connected and it caught, RPM on that but forgot to check dash.

So does the rev counter register when turning over before firing?

Next time straight to life again not checkable.


Trying to work out if crank sensor on last legs.

I do know I need a non return valve

The tachometer indicates just above 228 rpm which means if you see no reading the crank sensor's input is lower than that and you need at least 250 rpm input for the engine to start on cranking. The signal can be disturbed by the starter too if it's old

No sign at home time. but started easily