While I am driving down the road I see that the Rpms on my car will suddenly go up then down while my foot is still in the same place on the gas. My question is why does this happen. Also how do I know when I need new brakes. I have a '76 280Z.
I'm battling the same problem, check your vac tubing all around, EGR, Air reg.,cold start valve, and all the sensors at the front of the engine. it's a tough one. good luck.
what do you mean when to change the brakes; when the're in need of it!