okay, i'm close to nailing this one. here it goes. it's not the ignition switch, i had that problem before and replaced it. took care of that one. i'll start it and it'll run until i put it in gear and move (drive or reverse) it will then start to go haywire like it wants to die and it will. it will do this every time. when this happens i hear the ABS system initialize. the way i get it to stay running is when it gets past this point, after several starts, it makes it's whoosh sound as it starts to initialize and after that it runs without any problems whatsoever. all the lights and guages work fine. no check engine light, no flicker. i've checked the BATT, the ALT, the wiring, nothing loose or disconnected. i'm suspecting the ECM or ABS system but how to isolate them would probably lead me to the culprit. here's what i'm thinking, if i disconnect the ABS system and start the engine and it runs fine, then it was the ABS and not the engine ECM or will that cause another problem or mask it? also, what would i need to do to disconnect or disable the ABS? any suggestions?!

Welcome to AF
What year and engine?
Have you tested your fuel pressure?
Any codes or check engine lights?
Does not sound like a ABS problem But.
The abs fuse can be removed for a test or the abs computer unpluged for a test but do not drive it on the road disabled.