hey guys i am very new to this forum i have read alot, i just can't seem to find a solution to this problem i am having, or i am just not doing something right on my car.

car will start with a jump but will not start at all if i turn it off and try to turn it back on. i replaced the alt. i replaced the battery i fallowed the wiring harness and found all the grounds cleaned them up a bit. Bought a new ECU, checked all my connections on the harness. still will not start without a jump. anyone have any ideas