Originally posted by ez
Did you wire in your fcd with good soldering or crimping? It's either wiring or the MAP sensor going bad, given your changing of voltages of the FCD isn't really changing anything. Starting the car and testing shouldn't do anything, unless by testing you are touching wires that have poor connections thus leading to broken circuits. Also make sure your battery cables are tight - if not, sometimes voltages to your sensors can be inadequate and cause funky behavior.