305 cold start stall

hi i have 1993 4+4 when i start it when its cold it starts up then dies and when it stays running the idle is up and down and it seems like its worse in a gear, iv replaced some parts like egr valve , mapp sensor ,tps i dont know what it is

I'd look to see if you have an "idle air control valve"
If so this would be a prime suspect, providing you don't have vacuum leaks elswhere.

how would i check for a vacum leak

just so you know each time you replace a sensor you should reset the computer so it can re-calibrate for the new sensor. check for a vacuum leak with wd-40 or carb cleaner. shoot it around the intake gaskets, tb base gasket(very common leak area) and the various vacuum lines. does it drive alright?? i'm guessing the ECT(engine coolant temperature sensor) or maybe the IAC(idle air controll) the ECT acts like a choke. you might wanna check the fuel pressure too. the tbi regulators aren't too reliable. good luck