l have put a 2003 dodge neon engine in a 2002 dodge neon and it will not start l did have to re wire the crank sensor because it is on the front by the oil pump thingy and the crank sensor on the 2003 is on the block under the starter did l do something wrong or what because l am getting fire and fuel and it does turn over and try to crank but just wo not ..

Again, you need the 03 computer and harness in your 2002 car.

The 03 computer knows where the CPS is on the 03 engine, and that makes your spark timing in the wrong place.

Cranking is what the starter does, that is also called ''turning over''

''catch on'' is what happens when the car actually starts running.

try bleeding the air out of the fuel system if it gets any air in it which im sure it did it wont start until its bleed out,if its getting fuel & fire it will eventually start,the one we changed was stubborn to get started also,we had to prime the gas up on it to before we got it to fire,all ur other sensors hooked up fine right.so it will eventually start,you did not do anything wrong,it will eventually start,try priming the fuel up & see if it starts that way ,they will air lock when the fuel system has been open on them like that,good luck.