I drive a 90 LS and the needle in the tach keeps fluctuating. My car runs fine and there's no messed up idling. The needle goes to it's normal position (meaning which ever rpm it should be at) when I step on the gas hard. But when I go easy on the pedal, it begins to jump around again. Can somebody help me out here?

 

prob distributor, but you could try just replacing the ignitor.

try/check wires and plugs also.

 

dizzy

 

deff the dizzy

i had this problem a month or two ago

replaced the dizzy and no more problems

 

Hmmm...I just replaced my dizzy a couple of months ago. Is there anything else that could keep causing my dizzy to go bad?

 

Probly Loose ground or tach's starting to go bad... Check all ur grounds, especially the ecu ground.