I have a 97 f250 7.3. Ive replaced alternator, both batteries, positive and negitive battery cables, cam position sensor and glow plug relay and still wont start. Im about to set it on fire any suddestions?

 

whats it doing? have you scanned it?

 

Yes it scans code p1393 which is glow plug sensor which i changed. Its gotta be glow plugs so im changing those

 

good luck

 

If you have an ammeter, you can test them before you start throwing parts at it, check and make sure there is 12 volts at the connections. Could be a bad relay or blown fuse. If it is a blown fuse, your more than likely to have one that is shorted and bad.

 

I reread your post, and you did change the relay, still check for voltage and amperage. It may require you to have a helper to turn the key on while your checking it.

 

I changed the relay yes. Fuses all ok. Ive never changed glow plugs and have 425k on motor so prob need to change anyway. Doing tomorrow. Thanks

 

Its easy to meter out the glowplugs through the valve cover harness connectors. Just see if they measure a few ohms, or open circuit.

I strongly recommend rigging up a mechanical hpop gauge. You can also do a leakdown test on the hpop system with a porta-power pump. There's a good chance of a tired hpop at that mileage.

My E350 van caused me all kinds of grief, and in the end, replacing the hpop and ipr made it start reliably again.