So my daily driver (1996 f250 7.3) sat for 4 days while I was out of down this last weekend. When I returned, I expected it to take a few cranks because it had been unplugged and a bit cooler weather outside. To my surprise it cranks and cranks but no white smoke or anything. It is acting like it's not getting any fuel, any suggestions? My truck is just sitting in a parking lot right now...

 

1st get a volt meter and check the glow plug relay(under the darth vader looking engine cover) You will want to see only 1 volt difference between the input and output side of the relay(2 big studs)
If more than that, make sure the relay is being triggered. One of the small wires, cant remember which. The ECM GROUNDS the one wire to trigger the relay. The other small wire should be hot with the key

 

My wait to start light still comes on, i figured it wouldn't if that relay was bad?

 

The wait to start light has nothing to do with the GPR, besides indicating that the computer has turned the relay on. It doesn't mean the GPR is working.

 

The GPR is working, I checked it with a multimeter last night. Checked all the fuses under the hood nd dash. I realized last night that my WTS light doesn't come on, I'm almost positive that it did the day before. None of my gauges are working either. no tack or oil or anything. I'm thinking camshaft sensor is part of the problem? Still doesn't explain the loss of other stuff on the dash?

 

At this point I'm thinking ECM?

 

My scanner will not connect and i have never had an issue with that in the past.

 

Check fuse 22 under the hood. That is the ECM fuse, But it also powers the fuel heater. And when that shorts out(semi common) it blows the fuse and the ecm looses it power and it will not start and no communication with the scanner either.

But gauges not working is NOT related

 

it could be related if his ignition switch is faulty.

 

I am running out of options, all of the fuses check out. I sent the PCM off to have it tested and fixed (this has taken almost two weeks) only to find out nothing is wrong with the pcm.. Again, my issues are: truck cranks but won't start, no WTS light, no tach or other gauges, the scanner will not read the truck. I've checked the GPR, batteries, fuel pump, all fuses, and PCM. Any suggestions? All I can figure is something chewed on my harness? The truck sat for 4 days while I was out of town and when I returned, these are the issues.

 

Have you done basic things, like seeing if the ignition switch works, or if the main power relay is good etc...?

 

My 7.3 ps just gradually got harder and harder to start. It seemed to spin over ok but wasn't. I put a new starter on and the difference was amazing. And especially if the HPOP is getting old, it really has to spin good to build enough oil pressure to fire the injectors.

 

Ok, you need to borrow a good scanner that can read the diesel PIDS. At a bare minimum, to diagnose a no start you need to view ICP PSI, IPR Volt, and check for stored DTCs. You need to have at least 500PSI of ICP pressure for the injectors to fire during cranking. While cranking the IPR voltage should jump from 0.15 to 0.65-85 (depending on the scanner). Check for any codes related to crank position sensor circuit. Report back with these values. Without this info you will be guessing and throwing money away.