Engine Performance problem
2001 Other Infiniti Models 6 cyl Two Wheel Drive Automatic 30000 miles
2001 Infiniti QX4 30000 miles. It takes me 10 minutes to start it in cold weather (below 40F). To start it I turn the ignition switch on and off, without trying to start the engine, until I hear a noise (similar to a vacuum noise) from the back of the car, then starts immediately. I have already replaced: fuel pump, pressure regulator and pump relays. Could it be the fuel filter? It never fails to start in hot weather.