Hello, Terry;

I would start by looking at the fuel trim parameters (block learn and integrator counts) with the scanner; if they are above 128 it indicates that the ECM is compensating for an actual lean fuel mixture condition.

I would suggest checking these things:

(1) Measure fuel rpessure and volume to make sure they are within specs. A restricted fuel filter, leaking pressure regulator, or worn pump will cause a lean code every time.

(2) Check Oxygen sensor activity; especially crosscounts to make sure the sensor is active and not becoming sluggish

(3) Check for engine air leaks, or an EGR stuck partially open. In particular, these engines are known for developing intake manifold leaks.

(4) A lean running condition upon initial startup is often caused by excessive intake valve deposits and/ or too high an octane fuel. Both of these things result in lean running on a cold engine. Intake deposits act like sponges and soak up fuel on a cold start, making the engine starve for fuel untill they saturate. Fuel that is too high in octane rating (such as running premiul 93 octane in an engine designed for 87 octane) will result in the fuel condensing into droplets on the cold internal intake surfaces, untill the engine warms up, resulting in fuel starvation.

(5) Check engine coolant temperature sensor reading on the scanner; if the coolant temp is reading much higher than actual temperature as measured at the engine, this will result in calculation of injector pulsewidth that is too narrow, starving the engine for fuel and causing cold driveability problems like you describe.

A throttle position sensor problem will not usually cause symptoms like you describe' usually a TPS fault will cause severe hesitation and poor transmission shift quality. Check the TPS voltage on your scan tool; it should be below 1 volt at idle (most vehicles are typically around .75 volt closed throttle).

I hope this is helpful; if so, please click my accept button! Thansk!