My 1984 Maxima has a hesitation when you start out from a dead stop. It's much worse when you have the A/C on. Now that it's getting colder here where I live, it's a little harder to start in the morning. I took it to the Nissan dealership and they said it was the head temperaure sensor. I replaced it, but it still runs the same. Another thing is that it has terrible gas mileage. Can anyone help me please?

 

The Fuel Pump and Fuel Pressure Regulator are common problem areas with my car. I was experiencing a simular problem. Some yahoo mechanic had crushed my gas lines by misplacing the blocks for the lift. This caused my Fuel Pressure Regulator to wear out prematurely. I still have my original Fuel Pump at 160K miles.

In your case, you need to have access to a Service Manual.

1) Test Fuel Pressure.

2) Using a Voltmeter, run tests on all sensors used by the ECM (Fuel Management Computer). Sorry I don't have the specs.