I have a 2003 7.3 that someone installed a 2001 motor in. Because of this, the wiring is sketchy. The truck has issues starting when it hasnt been started in a while. Once it has been started, it will crank at the end of my work day with not even a half second of cranking ( i work 10 hours). Also, I had 12 ft uhaul trailer behind me with about 3klbs in it and I had no power and 7mpg.. couldnt get it to go faster than like 70, loss of speed uphill. oddly enough, i did not have this starting issue when i bought the truck a few months back.

I figure it either has a fuel issue or an issue with the exhaust/turbo.

The truck has all new fluids, filters.

When trying to crank the truck, if you lay on it (which i dont do anymore) i get a ton of smoke coming out of the hood (windshield wiper area). What generally happens is i get in the truck, go to turn it on, nothing. then i try again and again, nothing. After a while i decide that im going to take a different vehicle, 5 min or so later, i try the truck one last time and it starts almost immediately. It's really weird, it either starts immediately or not at all. It's not like a hard start that you have to crank for a while (that does nothing). Almost makes me suspect an electrical issue... i have many times removed the key and opened and closed the driver door because of this suspicion. Cycling the key 5 or 6 times before starting seems to have no effect (figured maybe that would prime the fuel bowl)? Cranking it doesnt help. Sometimes, I will crank it for about 2 seconds, realize its not going to start. then get out and come back 5 min later and it just starts right up..... suggests maybe IPR/electrical? I will have to check the fluid level.

I know the glow plugs dont work. I dont know if they ever will. The GPR is not hooked up, instead, one of the wires that connects to the GPR is connected directly to a relay on the fuse panel. Trying to put it back = no start... nothing. When i was looking into this, the issue i had suggested there was an ECM issue, so someone bypassed the gpr. At the time i noticed this issue, i had no starting issues whtsoever, so I left it. I also had number 8 wire completely removed from the harness on the drivers side valve cover. I did replace the GPR with no luck. I've got two 'extra' wires in to the cab, one of which i cannot trace (goes into the harness by the battery terminal and down below the engine, red wire, thick), either of which will cause a no start. Many of the wires on this truck have been burned (with a lighter) and spliced into.

As for the lack of power and eating fuel (nothing odd out of the exhaust)... suggests possible low boost? I do not have any gauges, but I have removed the fuel tank and cleaned everything out, cleaned and replaced the little valve in the fuel bowl. if I leave the fuel bowl open when i start the vehicle, I lose gallons of fuel in what seems like seconds. I know this isnt a definitive test, but I believe my fuel system is working. Perhaps the smoke when I have to crank it a lot and the low power indicates an exhaust leak? Only I cannot find any obvious signs of one. My next step is to take apart and rebuild the turbo and replace the uppipe seals.... but I dont really want to do that job if i dont have to.

Any ideas? As you can see, this truck is not likely worth taking to a dealer due to the engine mismatch and the general condition. I'm better off scraping it than paying ford more than the value of the vehicle to tell me whats wrong. But since it runs great when it runs (except the power issue), I hate to get rid of it.

 

Well I would say based on some of what you said the you have up pipe issues for sure. Also it sounds like somebody as done some hacking and hewing in the wiring and until that is straightened out you are most likely just spinning your wheels and getting no where.