Problems after rebuild oil sender and rev counter
 

Hello, I’ve just finished rebuilding a 1993 Auto RX7 Efini, it started first time after the rebuild so i was well chuffed. I've driven it for about 300km and noticed two problems, any help would be appreciated.

1. The oil pressure unit seems to work intermittently, it usually sits about half way and increases and decreases as the revs build and drop (okay that's good), then all of a sudden it will drop to zero. What the best course of action as there are lots of threads either saying replace or clean? Has anyone fitted a mechanical pressure gauge?

2. The rev counter sometimes flicks, I’ll be driving 2500 rpm then it will suddenly jump to 6000 rpm (this is only the counter as the engine stays calm). Also when I take my foot of the accelerator, the rev counter drops down to an idle speed (800 rpm).

Lastly what’s a recommended break in mileage for the engine?