Series 1 3.8 FHC Rev Counter

[andy486]

Can anyone offer some advice on a bizarre issue I have with my car? Driving up the A30 the other day, cruising around the 70 mph mark, I noticed that the rev counter dropped 500 RPM when the throttle was lightly pressed, then rose 500 RPM on the overrun, all without changing speed by more than a few MPH! Given the rev counter is driven by a generator on the end of the inlet cam I can't for the life on me think what would cause this. It was almost like it was being affected by manifold pressure...

[piman]

Hello Andy,

possibly the connections at the generator or the drive tang is badly worn and not driving properly. Relatively easy to check albeit a bit restricted in working space. (Held on by three Allen screws)

Alec

[andy486]

Hello Andy,

possibly the connections at the generator or the drive tang is badly worn and not driving properly. Relatively easy to check albeit a bit restricted in working space. (Held on by three Allen screws)

Alec

Thanks Alec,
Yes, must be something silly like a poor connection, maybe the movement of the engine, as it transitions from pull to overrun, is enough to disturb it... Will check it out at the weekend.
Andy