Hello! First time posting on this site. I have a 1996 Suburban 2500 with tje 7.4l in it. Four wheel drive. Had an intermittent issue where it had to crank for 30 seconds to start, then ran fine. I put a new Crankshaft Position Sensor in it, and now it just cranks and wont start. Also has a new ignition control module and ignition coil. Not sure what else to do! Any help or advice would be appreciated!

 

It the vehicle showing any codes?

 

Check the fuel pressure. You can also spray some fuel or starter fluid into the throttle body. If it runs for a few seconds then you need a fuel pump.