I have a 1997 ford f150 xl extended cab and i have replaced the fuel relay,the fuel filter, as well as the crankshaft positioning sensor and it will not start. It acts like it want's to for about 3seconds and then it dies i don't know what else it could be i would appreciate any advice or help on what it could possibly be thank you

 

This is the '87-96 forum. Your truck is different.