Sorry it took so long for me to get back with ya, work's been kicking my tail lately - just today we had a PTO pump shear off and cook a transmission on the side of a mountain.

I was going to offer to send you my injector cutout tool (AKA a couple harnesses wired together to plug inline to the UVCH and you are able to cut out injectors without going under the valve covers). The video able to pick anything up when cutting injectors out?

 

Dude, that does not sound like a fun breakdown. I'm guessing that isn't something that can be fixed, just a new transmission or rebuild. Sometimes you gotta get her home however you can:


I really appreciate the offer and would have probably taken you up on it a week ago. But after pulling both valve covers and doing the inspections and tests the long way, I have convinced myself thoroughly that the injectors need to be gone through again.

I was going to build a box with relays, but 100-120vDC at 8 amps is the spec I found and the relays I want to use are only 30vDC, I was concerned about the spark gap for the higher voltage. To use higher rated relays would have been costly and bulky. So I pulled the individual connectors- no luck isolating a 100% failed injector. I think one or more is partially stuck or has debris in it.

Still don't know where the debris would have come from??? The truck had the old oil when we tried the initial start (which never did start until we sent one no-oil-flowing injector back), but after sitting a few months, all the oil should have been in the pan and pass through the screen and (old) filter. Same with the fuel filter.

Not sure changing the oil ahead of trying to start would have made a difference? Only thing I can think is plausible is debris in the fuel or oil rails from the original injector failure (still think it was internal orings).

In about an hour or so I am pulling the injectors and packing them up- if it doesn't rain. Garage is full, I'm in the driveway.

Thanks again for the offer!

 

Seven out of eight injectors looked fine and normal.

Here is #7



So they are all going back to be checked. I didn't clean this at all, it isn't baked on hard, I could flake/rub it off.

While it is gone, I am allowing the oil to drain from the rails into the cylinders (because I forgot to remove the rail drain plugs last night like I wanted ). Once it is drained, I plan to run the borescope down the cylinder to check it for any problems and inspect the cup.

I suspect is is just a plugged up injector? It was spitting oil, though I don't know what is normal.

Any tips what to look for in the cylinder? Any reason to check valves or the doodleshlonger? LOL.

It also ohm'd just fine as posted earlier.

Anything else that could cause that?

 

By no means am I an expert on this ,but here goes. At the very bottom there's that copper compression washer, which is supposed to seal the injector to the cup, and thus the cylinder head, so all of the combustion stays in the cylinder. That o-ring right above the black keeps fuel from getting to that area. So nothing should be there and nothing internal to the injector should affect it. Internal leaks in the injector would come out around the nozzle, but that's still inside the washer and inside the combustion chamber. Both the copper and o-ring seal against the cup, so maybe a bad cup. If the o-ring leaked that area would fill with fuel and maybe get cooked, but it's still a sealed area.

 

Thank you for the insight.

I've seen multiple injectors with that cone burnt from blowby up out past the copper washer. This stuff isn't burnt on, it is flaky...maybe coolant? But I don't think it is burnt, coming up through the copper washer. You know, that does sound like a cup, doesn't it?

I replace #2 cup because I noticed it. I haven't checked the others. Under normal circumstances I would have replaced all 8 while doing it, but it was a struggle to get just the one done at the time. Perhaps I'll order another set and do the other 7 while she is apart...

 

Interestingly enough I've thought about doing that to many of our trucks some days - just without me in it!

Without looking at that washer closer, Im pretty confident that's from the combustion chamber. The crap on the lower fuel o-ring stops about 1/3-1/2 the way up, right where it'd be sealing. It does make sense though, it was the loosest of the octet.

 

LOL!

After chatting it over with a diesel buddy, it is more likely the copper oring didn't seal, allowing the combustion up on that part. Not long enough running time to burn it in yet. Could be a bad cup, but more likely something got in that hole or the copper washer wasn't sealing, etc.

So...if the rain holds after I go move a piece of equipment for a relative, I'll clean up that hole and scope it. If I don't see any problems, I'll pressure test the cups via the coolant line and tank. Depends how cooperative the borescope is. The usb connection and light is touchy.

Hopefully I find something, can clean up the injector, pull all the glowplugs and crank to empty the cylinders, reinstall glowplugs and injectors, top off oil and crank with harnesses unplugged to circulate oil. Cycle key to run fuel pump, etc. Normal injector install routines

Maybe I'll get lucky!

 

At least you found an identifiable problem, that beats taking it all apart and finding nothing. Congrats on the progress.

 

Agreed. Thanks!

I much prefer finding the problem over not knowing. I really didn't know where to go from here before finding this problem...

Tractor moved. I'm looking for the procedure for pressure testing the cups...

 

Coolant pressure test for cups???

I saw where Tugly made reference to draining the coolant before pressurizing the system to test for leaks. Is that a necessary step, draining the coolant first?

I am having trouble locating the test procedures. Anyone have a link?

 

I never saw a link but here's my $.02 on it...drain water down below heads, air will pass through smaller crevices than water will. Pressurize system through degas bottle and spray around cups with a light oil like WD40 and look for leaks. I wouldn't pressurize much past whatever the system pressurizes to when in operation but I don't know what that number is. It's whatever that cap is rated for.

 

15 psi comes to mind, but I am not sure on that.

 

I wouldn't go much above 15. The loctite sealant is meant to prevent leaks, not hold it in place The injector does that. Too much and I suppose one cup could pop out.

 

 

Left over washer? Ooooooooh.....