Hello Everyone, Need some help. My Son is and active US Marine currently stationed at Camp LeJeune, NC. I live in Hawaii. So, please be patient in my responses back to you all because I will need to relay your advice back to him.
He just finished a complete rebuild on the original 4.0 motor (5-speed manual SD) 1997 Discovery. Everything has been replaced from the bottom up. But, he has not been able to get it started. It cranks over just fine. Sounds really good, but never fires up, not even a little bit. We drained the old gas, made sure it got good and primed before attempting to start it. The only thing we have not reinstalled is the exhaust system. Just have the exhaust manifolds on. No clue if it matters just throwing it out there. A check list of some type may help, but you guys are the experts.
Your help is greatly appreciated. Mahalos

Kauai, Hi

 

Have you checked for spark? Upstream O2 sensors shouldn't be needed, will run in open loop. Crank and cam positions sensors installed and wires not iffy?

 

Fuel pressure? Maybe double check all the wiring connectors. Make sure a wire didn't push out of the connector and everything is tight, or the plastic didn't break in a bad way. I believe the ECM needs to see the crank sensor before it fires the injectors.

 

The inertia switch? I think it will still crank but not give fuel.

 

When you say good and primed, did you check pressure at the fuel rail?

 

There is a push button in the engine bay that is used to reset the inertia switch. It shuts off fuel after a crash. I recall mine needed to be reset after a rebuild. It makes a click sound when resetting.