Hi folks please tell what could be the problem, while i'm driving at freeway speeds, and usually in 4 or fifth gear, the tach start to jump back and forth between 3,000/4,000 rpm what could be the problem, this all happen after i installed the camshaft syncronizer, everything runs pretty smooth, and have been for at least 2-3 weeks, with the exception of the erratic behavior of the tach, please let me know your inputs.

p.s i have checked for vacuum leaks and any loose connections, and all seem to be okay.

 

the speedo is electric

you are thinking aboot the rpm tach

sounds like a bad sensor

 

yes thats correct