I dont get it.....I keep getting the code for my TPS sensor on my 86 Olds 442 ...I replaced the sensor with an ACDelco TPS....The check engine light come on every now and then. I ready to give up,,,,,,,Anyone got any ideas. If your in IL text me please. Im not on the computer that much. Thanks 815-483-4679

 

Also my RPM gauge is way off....It s going crazy

 

Start checking your grounds. Make sure all of them are clean and have good contact. Ground straps from the engine to firewall, all wiring, and even the gauge cluster.
The tach has this as a common issue with the 6/8 cyl selector getting loose and reading like a 6 cyl.