Outer Limits 4x4 Board

Hi all, ive got an 88 GQ swb petrol/gas....... quick question, the tacho in it bounces all over the place and i was just wondering how it is wired up cause im thinking it is a loose connection or something, also the oil pressure guage isnt very accurate (ie: sitting on idle it can be sitting on normal then drop down to 0 then come back to normal etc)

Cheers
Ryan

itl be one of a couple of things

the dizzy has water in it, or the coil is on its way out or if its only happening on gas the top of the carby is loose!