ok so the saga continues... the list of components replaced grows
ignition module
coil
plugs
plug wires
cap
rotor
idle control valve
vaccum lines (including flame trap and restrictor T)
now down to the problem when the rover is started from cold it runs and idles fine no problems nice and smooth and everything. after it idles for awhile (15-20 minutes) when i put it in gear it dies. when it first started doing this it was throwing code 48 (stepper motor) hence the replacement since doing so it hasnt thrown the same code or any code for that mater. ive also set base idle speed and its right where it should be. needless to say im stumped ive heard some talk that a bad alternator could possibly cause these sorts of symptoms any thoughts or ideas? i really dont want to keep throwing parts at but i want this thing fixed so i can enjoy it again instead of wanting to set fire to it

anways thanks in advance