Ok new to group, need help bad. Ill start from the beginning. Motor in my 2014 chevy 5.3 started making a squealing noise, though it was belt, took off all belts buddy says i spun a main bearing. Got used engine, installed and now no run. My code scanner said p127c fuel pressure sensor along with several other codes all dealing with fuel. Found out from 14-16 gm used a 4 pin sensor, 17 up used a 3 pin connector, wiring harness for the sensor and drivers injectors was bad on old motor so i ordered a new 1. Put in new 4 pin fps and harness and still no run. I have checked all grounds, both plug ins on back of intake (they r in the right plug i checked colored wires to make sure), changed all sensors on engine. Buddy came today with snap on scanner. Cleared all stored codes, tried to crank and the only code we got said alternator not charging. Could that b my whole problem. Ive been working since last friday to make it run and im out of options. Plz someone help

 

Welcome to the forum. If you haven't already, you should post your question in the particular section of the forum dealing with your vehicle. This is just the Welcome New Members section.