Erratic Tach

I have a tach that is erratic and the engine light comes on, and it is hard to start. I recently went on a trip about two (2) weeks ago, hat is when this started. While I was on the road the tach started bouncing up and down and the engine light came on at the same time, I lost speed down to 45mph and it stayed like that for about 7-10 miles and the light would go out, tach stop bouncing and you could fill the power jump in and it get back to the cruising speed.

Could this be the camshaft sensor or if anyone has had this problem please let me know what it is before I take it in to be repaired, I would love to do it myself..

2001 Georgie Boy Landau
L6 5.9 Cummins ISB
2002 Saturn LW 300 Toad


Senior Member
More than likely a ground to the tach or a plug on the cable from the motor to the tach input that is corroded.