Hello folks,
My engine started misfiring, I changed the UVCH, and it is still misfiring. Whole drivers side does not fire.
My question is: I have ohm'd out the injectors and glow plugs at the valve cover harness connector and everything is fine.
The buzz test revealed #2 cylinder as being very quiet, but again, it seems like all cylinders on that side aren't firing (no heat for that side after idling for a bit).
If it all ohms out within specs am I done with looking under the valve cover?
Is it time to test the wiring from the IDM? (and the IDM?)
For what it's worth, this truck is like new, way under 100k miles on it. hasn't been driven in several years. It's not a worn down old truck. But I know things happen when it just sits.
Sorry for the same old question, I am just looking to know what my next step should be.
Any help is appreciated...

p0276
p1272
p1274
p1278
p1294
p1316

-1997 7.3

 

Check the wiring by ohming it out at the IDM connector. If it is good then pull the IDM and shake it to see if water may have gotten inside.

 

https://www.ford-trucks.com/forums/1...load-test.html

pic of ohm test to do in above link

 

I guess that is the next thing to do. I have just learned that sometimes the IDM will shut down the whole bank because of one bad injector. I'm going to look into that too.

 

Thanks for that link, it has an excellent diagram on it. Very helpful.

 

I'm still having problems. Fortunately this isn't my daily driver. The buzz test has become revealing. I attached a video of it. The video starts during the all-injector-buzz. You will hear 8 injectors buzz...the problem is that I have the 5&7 connector unplugged, Am I supposed to hear a little buzzing when a connector is unplugged? you can also hear the IDM make a sound once the test is done. #8 always sounds like that when this problem is happening.
This is a truck that has sat for several years, very low miles.
#8 injector sounds quiet, I switched injectors (8with6) and the sound did not follow the injector.
Whole D-side bank is off.
Injector 6 has oil coming from it like it is supposed to, yet not firing.
Injector 2-4-8 has no oil and not firing
I'm still getting P0276 (Injector 6 circuit low)
**the above was yesterday after switching injectors, I idled the motor until it was warm(on 4 firing cylinders). Did one more buzz test. Same results. Done for the night.
Next morning I did a buzz test. All 8 injectors sounded good. Truck started up and ran fine. (I did nothing but buzz test, then start!) (it fixed itself overnight)
Shut it down, then started up 30 min later, D-bank not firing, Buzz test showed #8 as quiet again, P0276.
Ohm tested from IDM to Injectors, NORMAL.
All Ohm testing of anything comes up normal and I've never gotten bad numbers.
Does this buzz test confirm it is the IDM?
How can an injector be good yet not exhaust oil? Can the IDM shut off the injectors and oil exhaust? This is the confusing part. When bank is off, oil from #6 only. Next morning Bank is firing with full oil exhaust all injectors.
ICP readings are always normal to slightly high (usually normal even when bank is not firing)
Normal IPR duty readings
I changed o-rings for any injector I removed.





unmodified 7.3
new UVCH

 

I just went thru this in the thread 'opinions please!' If you have a spare IDM try it. Then you might have to take apart the engine wiring harness and look for bad wires. Good luck!

 

If it sat for a few years i would be highly suspect or rodents making their way to the wiring, or bad fuel damaging the injectors. Dump 2 stroke oil and some seafoam directly to the fuel bowl and see if that helps

 

I've checked the wiring many times and it comes normal. Ohms are normal from idm to injectors.
Here is a new video buzz test. Passenger side completely disconnected and the drivers side gets buzzed when P-side is supposed to buzz. I don't think this is normal is it?
Truck was stored in 60-80 weather year around, inside an enclosed canopy, no mice.

 

Well now we get to see a great example of what happens when you try to revive a motor that sat for a few years without cleaning the fuel bowl. My bad, I should know better. Fortunately I have only went around my block at low speeds about 4 times during all my issues. Lots of idling. That is likely how it survived. Funny how it only affected one bank of injectors though.
This also shows what the '97 7.3 IDM will do when a couple injectors get clogged up. It will shut down the whole bank, make the engine run 'kinda smooth' on 4 cylinders. This would explain the Buzz test as the IDM was configured for 4 cylinders with D-side bank shut off... my theory anyways.

 

water sensor wasnt working?

Good find. I dont know if the IDM can detect water in injectors. Hopefully you didnt run them long with water to damage them.