Another No-Start 7.3L
If still bad at uvch, then pull valve covers, inspect uvch and check the injectors themselves by unplugging the uvch. This could be as simple as 50 cent mod, or replacing uvchs.
I'd bet on just bad connections, but if you decide to replace solenoids, while you've got the solenoids off, check the clearance of the armature plates on the injectors to see how much clearance there is under the armature(should be around .004)
Driver Side
Driver Side
Passenger Side
Passenger Side
While cranking, the IPW needs to be at least 0.6ms. This indicates that the PCM has established connection with the IDM. If not, the IDM will not fire the injectors because the PCM can't tell it to.
Just to add it here for any future internet searches here are the minimum parameters that need to be achieved for the engine to start (all of this is while cranking):
1. Engine RPM - 100
2. Injection Control Pressure (ICP) - 500 psi
3. Injection Pulse Width (PW) - 0.6 ms
4. Volts - 7-10 VDC
- Buy some electrical contact cleaner and dielectric grease, then clean out your IDM connector and re-grease it - the IDM gets hammered with water from the road, and you want that grease to protect it the connector. While you're at it, cleaning and dielectric grease is good in all the connectors on a diesel (focusing first on the sensors you have touched).
- I would take some Simple Green and spray that engine down real good, let it soak, then gently rinse it with an open hose (not a pressure washer), being careful with what you rinse. A leaf blower or a shop vac in blow mode can dry things out.
- After things are clean, look around for wire insulation rubbed off where wires touch metal - particularly under the wire bundle to the 42-pin connector on the driver-side valve cover.
- Rather than be concerned with a $500 wire harness, I would click this: https://www.ford-trucks.com/forums/1...r-pigtail.html
- Using the non-mobile site, I would click the links in my signature - one link in particular makes testing the UVCH much easier.
- Pull the chip out completely before your next attempt at cranking. If this resolves the starting problem, this does not mean you have a chip problem - it likely means you have a chip connection problem. I have this tee-shirt in my drawer, right alongside that bad VCCP tee-shirt.
- Buy some electrical contact cleaner and dielectric grease, then clean out your IDM connector and re-grease it - the IDM gets hammered with water from the road, and you want that grease to protect it the connector. While you're at it, cleaning and dielectric grease is good in all the connectors on a diesel (focusing first on the sensors you have touched).
- I would take some Simple Green and spray that engine down real good, let it soak, then gently rinse it with an open hose (not a pressure washer), being careful with what you rinse. A leaf blower or a shop vac in blow mode can dry things out.
- After things are clean, look around for wire insulation rubbed off where wires touch metal - particularly under the wire bundle to the 42-pin connector on the driver-side valve cover.
- Rather than be concerned with a $500 wire harness, I would click this: https://www.ford-trucks.com/forums/1...r-pigtail.html
- Using the non-mobile site, I would click the links in my signature - one link in particular makes testing the UVCH much easier.
- Pull the chip out completely before your next attempt at cranking. If this resolves the starting problem, this does not mean you have a chip problem - it likely means you have a chip connection problem. I have this tee-shirt in my drawer, right alongside that bad VCCP tee-shirt.
I was able to get the main engine harness removed, but as soon as I did, my 9-month old woke up and I haven't had a chance to inspect it yet. Gonna be out of town until tomorrow night so it'll be Monday before I get back to work on the truck. I planned on cleaning the harness up and cleaning the connectors with contact cleaner like you said. Also gonna replace all of the plastic protective sleeve and get rid of all the old electrical tape. I'll have to drink a beer or two to calm my nerves before cleaning the engine up!
I can't help but feel like I should go ahead and replace the UVCHs on both sides while I'll have everything pulled out and cleaned so I'll more than likely go ahead and do that. I feel like I read that the gaskets generally hold up well and don't need to be replaced but I'll go back and research that more. Do you think I should i go ahead and order the gaskets with the UVCHs or am i likely to find that they're okay? I'm definitely getting international parts btw, read to many bad things about the Dorman and like brands
I'll make sure to check out the links when I get to my laptop.
Ford Trucks for Ford Truck Enthusiasts

I got a chance this weekend to strip all of the nasty electrical tape and wire looms from the harness, cleaned that up best I could, and also cleaned the engine best I could. I sprayed in down with the simple green, let it soak and rinsed with the garden hose (spicket barely cracked open). Took the leak blower to it from a good distance away at first, but couldn't shake the thought of possibly forcing water into placed I don't want it - just like a pressure washer would. So I decided to just take the shopvac and PULL all the water away instead. I felt better doing this as it helped me get all of the water out of the valley, as well as the electrical components/connectors....but I still hate washing an engine lol lets just hope I didn't create another problem

After going through my wires, I have a question regarding some findings. On the IDM circuit, I found that the 4 injector wires and the common center wire that run to each UVCH connector and the main engine harness connector, were separately wrapped what looked to be a insulated tape, and then electrical tape. Underneath all of that was a bare wire that wrapped around the length of the 5 wires, and is coming from the main engine harness connector (pin 15). This separate "bundle" also had a tag on it with the date and time the harness was made and tested...……..Now, I've never seen the inside of these wire harnesses, so I have nothing to go off of. It all seems to be original; nothing seems to be rigged together any worse than from factory lol. I haven't been able to find a good pinout diagram for this connector, but I'm assuming this is a ground wire that's been wrapped around these injector signal wires in order to block any sort of unwanted frequencies/noise....can anyone confirm this? If this is the case, does the bare wire need to be connected back to itself? Pictures below
Anyone have a spec or P/N on this insulation/tape?? Need to get some to re-wrap
Definitely needed replacing
Yup
IPR connector -> replacing as well
The wire from pin 15 of the main engine harness spilts into 2 bare wires. One is long and wrapped aroud the enitre length of the 5 injector wires; one is short. Do these wires need to be connected??
Can the dealership test an IDM if I bring it up there?













