Jack, thanks for reporting back to us. Even though you are safely at home and can take your time, we are still very interested in how you are getting on with the diagnosis and repairs.

As Leonard said, time to start testing from the IDM harness to the UVCH, at least on the drivers side. I would recommend to unlpug the IDM ASAP and before the next key cycle in an effort to preserve the $450 - $550 bill for a new IDM from Jonathan at DTC.

Below are some how-to's taken from the 7.3L PSD Tech Folder in order to help you with your testing. You will need a multimeter at the very least and another set of hands is helpful.

IDM - Injector Driver Module

• IDM - 42 Pin - UVCH Map
• IDM Replacement & Testing
• IDM Wire Map
• IDM Electronic Feedback DTC P1668 & P1670 (2002)

We are here and eager to help. Keep us updated!

 

Ok, sorry for the delay in posting. We had a death in the family that shook up our normal routine.

I have cleared all codes, several times while running tests. I have traced all the wiring relating to injector circuit #6 from the IDM to the injector. I replaced the UVCH on the drivers side. I tried a new IDM. No differences in how it is acting.

Currently, I can start the truck with every key cycle. It will run with a noticeable miss for 5-10 seconds, then drop in power and die. I am assuming that issue is the IDM getting a bad reading from injector 6 and then shutting down the whole drivers bank.

Buzz test shows a problem with injector #6. I moved the injector solenoid from #6 to #2 and re-did the buzz test. Now I am getting the same error on injector #2, and #6 is reading fine. On starting the engine, it is doing the exact same thing, idle with a miss for a few seconds, then dropping the drivers bank and dying.

I have messaged with someone from Bitterroot about just trying a new or used solenoid, his suggestion was to have the PCM tested. I don't have any idea where I can even get that done on a 20 year old truck. I have a friend with a '97 parts truck that I plan on getting a solenoid from just to try that.

If that fixes the problem, what's the general consensus on going with it like that, or replacing all the injectors?

Any other ideas or suggestions?

 

Jack, as I mentioned to you via text the other day, our heart goes out to you and your family during this difficult time for y'all. If there is ANYTHING I can do to help, don't hesitate to call or text.

As for the truck...

I would ask the source of the IDM, but if the problem moves, then I would not suspect the replacement IDM.

You can have the PCM tested by Jonathan at DTC and the link below.

Link: https://www.dieseltechchatt.com/prod...12361158393919

He is a stand up fella and will tell you straight, over email as well.

If the issue moved with the solenoid, I would suspect a solenoid or clearance problem. Although, I am not an expert on injectors.

If you swap in the solenoid from your friend and all is well, I would say run it like that keeping an eye on things. No reason to replace all of the injectors prematurely.

Injectors can die at 150,000 miles or sooner, but they can also go past 400,000 miles at times. I have 263,000 miles on my injectors and though they are tired, they are still getting the job done towing in WY and CO.

Ultimately, the choice is up to about replacing the injectors if the spare solenoid fixes the issue. If you are looking for a reason to replace them, this is certainly in that ballpark.

 

Yep sounds like a bad solenoid at the least. Sous pretty much said it all. The only thing I have to add is to ask if you've checked resistance on that solenoid and what the results were.

 

I did check resistance on those 4 injectors. #6 was different from the other 3, but not enough to make me think it was bad. I don’t remember the reading. I’ll be in the shop with it again this Saturday so I’ll check resistances again and post the numbers.

 

Finally found a donor truck. The others I was told about were all IDI and don’t use the same injector. My sons friend has an old wood getting truck he only uses a few times a year so I’m robbing parts from there.

Replacing the injector solenoid fixed the problem. I’m back on the road!

I forgot to check resistance on the bad solenoid, but I will when I get back to the shop.

Now I’m looking for someone who has a few of those solenoids they’re willing to part with. I want to add a couple extra to my traveling parts box. Any one willing to get rid of some junk?

 

Well, I have some core injectors in the garage, but only have 8 of them and will need the solenoids when I send them in to Bitterroot.

On the positive side of things, I am glad to read you got it sorted out. I cannot say that this is a common failure mode, but good on your for doing the detective work and getting it sorted out.

Travel safe sir.