Thanks Jeff, I did clear the codes before doing buzz test again and after swapping the injectors. I have the IDM pulled and am getting it ready to mail off to Chat Diesel. My engine harness is brand new, OEM from Riffraff. I did cut the other side loom (going to fender) on the 42 pin connector and inspected those wires. All looked good. I swapped out the UVCH and nothing changed. IDM is the only thing I can find in researching that it can be at this point. Swapping injectors didn't change anything. I'm really trying to avoid throwing parts at it and test and inspect what I can.

 

Update from Chattanooga Diesel:

IDM, PCM and chip all tested good. I have no idea where to go from here...

Any ideas? If I had any hair I'd be pulling it out.

I will be going back through the comments here to make sure I didn't miss anything.

 

It has to be wiring then. Test and wiggle the wires feeding Inj 4. Never trust new parts.

Look for bent or out of place contacts on the connectors along the way (at the injector solenoid, at the valve cover gasket, at the 42pin conn, at the IDM connector).

 

Whelp. I got my PCM and IDM back from Diesel of Chattanooga. Everything back together and I just test drove it. Still getting engine service light, grrr...

I'm gonna swap the IPR for ****s and giggles and jiggle the wires more even though the engine harness is new. I am not getting a code specific to any injector now.

I'm getting a bunch of weird ones. When I just test drove it, she runs great, tons of power, roasting the wheels, etc. But it is intermittent. When the service light comes back on she lugs a bit and I don't hammer on it cause I'm worried I'll make something worse. It seems to me the likely culprit is wiring...

I will will update everyone in a few days again. I need to step away for a bit.

 

Update:

I thought I found my issue but I have not. When jiggling the nine pin connector a few times the service engine light would go off/on but not often.

Even though my UVCH harness is new I did the 25 cent mod (one side of the 50 cent mod) and no change… if you read earlier posts you may remember the engine harness is new.

The only thing not new or swapped out is the harness going to the 42 pin connector. I looked at this where it goes over the valve cover and it looked good. However I’m out of ideas. So I’m gonna pull back more of the loom after removing the electrical tape I added and look really closely with a bright light.

This is so frustrating!

 

I pulled the truck into the workshop yesterday and dug into the harness going to the 42 pin connector this morning. I pulled back the loom and electrical tape, again, and really looked at each wire, with bright lights. I check dirt spots to ensure that was what they were by rubbing with my finger nail. I looked at each wire from different directions going about 8-10 inches back from the plug.

Then I sprayed the pins with electrical cleaner. I scraped each pin with a small screw driver to get any corrosion off. Then I sprayed it with the cleaner again. Finally, I rubbed some dielectric grease on there on the female side before putting it all back together.

I went to take it for a test drive. The battery light came on. I tried to run live data anyway with forscan and a usb wire going to my laptop and the obd 2 port. Every time I tried to run live data the truck would die. It drove good but couldn't get live data...

Anyhow, then I tested the alternator with a clamp on amp tester/reader. I'm getting zero amps from the alternator. My batteries were low a few weeks ago but I thoguht it was just from it sitting and my working on it, draining them down. I topped them off with the charger and didn't think more about it.

Now I have an alternator getting ordered today, most likely from DB Electric. I like their quality and customer service. I gotta get the charging system corrected before continuing on. Fingers crossed that my issues are from low batteries. Also, the batteries are about 1.5 years old so I think they are still good and will hold a charge.

Let me just bang my head against a wall (or steering wheel)...

 

Did you have your alternator tested? if the field isn't turned on, it won't charge.

 

i tested it by checking amperage coming through the wire to the battery (the thick one). Alternators for the 7.3 are internally regulated so I just replace when they quit working. Is the field thing easy to repair? I never got around to ordering one yet. I’m all for saving $150 plus shipping if possible. This alternator has only been replaced once about 15 years ago. The original OEM crapped out while camping in Death Valley with my kids. I changed it out in a parts store parking lot. Don’t remember which one now.

 

I had partial luck replacing the voltage regulators inside these OEM alternators. rebuilderinabox.com had the kit. The replacement in my upper alternator did not last long, but the lower one is still going strong. I wanted to understand how they went together, and with dual alternator redundancy, it was no big deal if one went out again. In your case, I'd recommend a new replacement. I recently put on the 135A Bosch 6.0L AL7606N. Minor mods to the mounting bracket and it fits, at a reasonable cost.

 

Thanks Jeff, now I'm going down the 6.0 alternator upgrade rabbit hole! haha.

 

Hello All,

Brief update: I got the new 6.0 alternator in. It's a beast! Same price as the 7.3 one but 180 amps! I think the 7.3 one is only rated at 110 amps.

Today I pulled the passenger side valve cover. All of that wiring looks new and no chafing. I did the 50 cent mod on this side and am putting it all back together. This is all new from about 1000 miles ago, OEM from Riffraff. I test drove it the other day and my truck has plenty of power. I drove it like I stole it on the interstate 90 mph and she didn't miss a beat. I still have the engine codes P1316 and P1380.

The only thing I have not swapped out is the IPR valve. It's new OEM already but I may put the old one in to see if it makes a difference. I'm at a loss...

The only thing after the above that I can think to do is pull out the new OEM engine harness and put the old one back in to see if that does anything....

Everything in the system is either new or swapped back with a known good old one. Any ideas are welcome. If you remember from earlier in this thread that everything just about, has been replaced.

 

Hi All,
I'm poking around the wiring harness and realize there are two plugs, both with brown boots that will both fit the IPR valve. I drove 1000 miles without any issues so I think I had it connected correctly but I thought I would ask here.

The plug that has been connected to the IPR Valve has a solid red and a yellow/red wire. The other plug has a red/white wire and a black/white one, which has been capped off.

Are these correct or did I miss something? They are both located in the middle of the engine, near the HPOP and IPR valve.

 

The other goes to the ebpv I think. Don't remember colors

 

Yeah, I’ll have to confirm the capped off one. I found a drawing showing IPR valve and I know that I had that correct now based on wire colors. She’s still starting and running fine most of the time. I didn’t run it long enough to confirm anything has changed though. I just needed to move it yesterday when I finished. I plan to haul some trash in it today so we will see how it goes.

 

Josh is correct. IPR and EBPV use the same connector type. I doubt it would be running very well if those were swapped.