Tacho Issues

[Jez33]

Hi All

im a newbie to the car scene and this forum, i just bought my first car a '95 R33 gts25t auto four door.

the car is in good condition but the tacho doesnt work, it goes up and down gradually but not on line with the RPM. After a little bit of a spirited drive the tacho often goes all the way around and just hangs vertically. At first i wasnt too worried as it is an auto and i wasnt too fussed about it. But some of my mates seem to think it may mean that the rev limiter isnt working, or that the turbo wont kick in (it feels like it does to me, but it is the first turbo i have ever driven). I realise this could probably point to 101 different things but it would be appreciated if you guys had some ideas of things to check, ways of diagnosing the problem, common problems etc.

cheers

Jeremy