When starting first thing in the morning the engine pulsates and almost dies 5 - 10 times then finally kicks in and starts running fine. Starts up fine the rest of the day. The plugs have been checked and gapped, the rotor and air filter replaced and the dist cap contacts cleaned. The throttle body and the air bypass valve have both been cleaned. Could this be the O2 sensor, some temp sensor or maybe loss in fuel pressure after sitting overnight? The car is a '95 non turbo w/ almost 100K miles.