engine idles fine until I shift into drive , as soon as its in gear it stalls oout. steping on gas pedal also results in stalling .what could the problem , or where do I start my diagnosis?

What is your question?

stalls out when shifted into drive and when gas pedal is pressed to start from stopped . engine will idle fine until put in drive, it stalls right away and gasing it does not get it to remain running .

What makes this problem better or worse?

nothing seems to keep it from stalling once its put in gear.

How long has your 2002 Mazda B3000 had this problem?

started after I removed the gas tank to do unrelated repairs. changed inernal fuel pump but had no improvement.