I just bought a 04 5.9 that isn't running. I have seen it run recently but it would run at times and just quit. So far I have done the following:

Tested the in tank pump by jumper wire. It runs with jumper wire but not when key is turned on.
Unplugged the FRP sensor, no change
Tried to read codes by turning key 3 times...doesn't work
Tried to read codes with my code reader..doesn't recognize vehicle
Charged batteries and cleaned posts. Batteries are 12.6 V
Noticed that the voltage gauge does not come off the 8V post when turning key on
The Theft light comes on when turning the key on, goes off then stays on
The truck will crank just fine but it will not start. Any ideas on where to go from here. I hope the following info helps.

 

check the fuel pressure

 

there is none because the lift pump wont work with the key on and there is no fuel in the bowl. The lift pump runs fine with a jumper wire. Its acting like the ECM is not coming online for anything. I am wondering about the ground locations.

 

So, tonight I went through all the fuses and relays. They are all good. I even swapped a few out. I pulled the fan clutch plug and that didn't change anything. I cleaned all the ground locations I could find and still nothing. When I crank it I am getting no tach reading or oil pressure reading. And as I said earlier, the voltage gauge never comes off the bottom post. All the lights on the dash work and when I do the gauge test they sweep. I am at a loss as to what to do next. I wish I knew for sure how the Theft light was supposed to look. It comes on for a few seconds, goes off, then stays on solid. Is that right?

 

First, this is not my area of expertise so it is just a WAG....

I've seen similar once before and it was ECM fried.

See if you can borrow a known good ecm to swap out and try that.

 

I believe I have determined my ECM is DOA. I probed the 4 wires (cant remember the pin numbers) that should have 12v with key on and they were all 12.5V. I also probed the 4 ground wire pins with a test light and they were all good as well. Is there anything else to check that would tell me it is not the ECM that is bad?

 

Just fixed this problem 04 does not have fuel pump in tank unless its been put on after the fact what's in the tank is a fuel gauge it looks like a fuel pump but has no motor the fuel pump is on back side of filter canister I put a after market air dog system on fixed the problem run like a champ now

 

Its fixed...sorta. It was the SKIM key not communicating with the truck. Now that its running I am getting a lot of smoke after it sits for a while with a slight miss. It cleans up in about a minute or two and the idle smooths out. Injector leak. How do I go about checking this?

 

Not sure if I'm following you correctly.

The security anti-theft (SKIM chip/RFID key) was an option in the 2004 trucks. The chip keys are gray versus the black non-chip keys.

This system will allow the truck to start and run for about 10 seconds if a non-valid chip key is used.
The system will not prevent the truck from starting at all.

This is easily confirmed by just cutting a non-chip key for a couple of bucks at your local locksmith.

 

The way I understand it is you are correct but only for the first 6 tries. In other words the truck will start and run for 10 sec. for the first 6 attempts but after that it will not start.