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Injector troubleshooting, bad IDM?

24K views 24 replies 10 participants last post by  MonkeyWrench 
#1 ·
I have been troubleshooting a no start issue. I have verified the the UVCH is good, all injectors ohmed at 3 ohms, and .6 ohms for the glowplugs which are pretty new. I verified the HPOP oil level is full, and then pulled the valve covers off and cranked the engine. I have only 3 injectors firing on the Drivers side, and 1 on the passenger side as verified by oil coming out of the injector when cranking. I am going to do some continuity tests on the wire harness from the IDM to the valve covers. If that is all good, is it an IDM issue? When the initial failure happened the truck progressively lost power over about 5 miles until it wouldn't idle and then died, so it isn't like it failed all at once. Thanks for the help

Bill
 
#2 ·
You might start swapping out injectors. Put a known good injector in a dead hole and visa versa. Find a buddy who will let you borrow their IDM.

Plug the block heater in for a few hours to see if it will then start. Helps a lot diagnosing if you can get her to run. Have you tested your glow plug relay, and made sure she is getting fuel too?
 
#3 ·
How many miles on injectors?
If you could do a buzz test, that would tell you if any faults from IDM. harness,valve cover gasket connectors,solenoids. You could have water in the IDM. If injectors have alot of miles, you could have bad poppet valves and that too would not let oil discharge out of oil spouts.
 
#5 ·
You can get a buzz test done at any shop that has a PSD capable scan tool. If you call them and you get silence when you ask them if they can buzz test a Powerstroke, just hang up and move on.

Or you could track down a buddy that has an AutoEnginuity setup and ask them to do it for you.

What it does is initiate the test that's pre-programmed into the PCM. It buzzes all 8 injectors at once, then each one in numerical sequence individually. Listening tells you a lot, and you should listen for differences in the sounds of the individual injectors buzzing. If it passes, it tells you, or if not it will display the codes that the IDM has stored in it. It's mainly testing the circuits and the IDM, not the hydraulic side of the injector.
 
#6 ·
No all four injectors would not fail at once.
A bad IDM could cause that.
Water in IDM could cause that.
Short in harness could cause that.
Loose or burnt connector on valve covercould cause that.
 
#7 ·
You could pull the idm and open up the cover. If you see burnt components you know you have to replace it. There are four screw on the cover and then you have to take a box cutter to break the silicon seal. Here are some pics: IDM Mod
 
#8 ·
You could pull the idm and open up the cover. If you see burnt components you know you have to replace it. There are four screw on the cover and then you have to take a box cutter to break the silicon seal. Here are some pics: IDM Mod
That's a pretty drastic measure which I'd save till I'd exhausted all other diagnostic measures (like getting the codes out of it). If it isn't bad, then you just have to reseal it (unless you feel like doing the IDM mod to it).

BTW, there are NO screws holding the cover on, just the RTV. The cover is glued on there pretty good and you'll likely bend it a bit getting it loose.
 
#12 ·
When the initial failure happened the truck progressively lost power over about 5 miles until it wouldn't idle and then died, so it isn't like it failed all at once. Thanks for the help

Bill
I'm sure you did the obvious, but I didn't see where you verified that you are getting fuel.
Randy
 
#14 ·
Yes verified getting fuel. Pulled the IDM, looks factory new in there. Started swapping injector wires around and the got a bright idea to spray a little bit of ether in the intake and see if it would start. It started and I gave it a little throttle to rev it up and held it around 2000 Rpm. Low and behold all the injectors started to work. Initially I was low about 2 quarts of oil, I added oil to the engine and the HPOP res was full, but if the injectors ran low on pressure could they have locked up? everything is fine now and buttoned back up. Wow what a learning experience! Truck runs like it always did!

Bill
 
#13 ·
I was thinking fuel too... filters are relatively cheap.

That box, does it control the wipers too. When I picked up my F250 the told me the wipers were connected to a black box and they were not working. The dealer put a momentary push-button in the dash to run the washer moter rather than replace the "black box" ata cost to me of $500.

???
 
#15 ·
I have been troubleshooting a no start issue. I have verified the the UVCH is good, all injectors ohmed at 3 ohms, and .6 ohms for the glowplugs which are pretty new.
Bill
I am chasing problems with my engine, low power and miss when first started. I ohmed the injectors through the VCG and mine were 1.1 to 1.9 ohm's. I did the same on the engine I pulled out and they were all 3.0. Does this mean the injectors are bad? Someone else said doing this didn't mean anything. Any help?
 
#16 ·
At the Rosewood Diesel website, they claim that higher mileage solenoids show a resistance closer to 3.0 ohms. If you sent them your injectors for a rebuild and they showed that resistance they would replace the solenoid also. They like readings below 2.0 ohms. Somebody in this forum said they are the company that supplies Swamps with their injectors. Everybody here that I have read is very happy with their Swamps injectors.
 
#17 · (Edited)
So if they are in the 1.0 to 2.0 range are in good shape? Thats lower resistance or am I wrong?

Okay looked at the Rosewood site and looks like these are in bad shape. What's strange is I swapped #8 injectors to get rid of the LL. I ohmed the LL and its at 3.0. The AD in #8 is at 1.9. Could the IDM malfunction and screw up the solenoid? Or when the injector cups were bad enough coolant went through them to ruin them?
 
#18 · (Edited)
So if they are in the 1.0 to 2.0 range are in good shape? Thats lower resistance or am I wrong?
Yes the lower reading means lower resistance. I didn't catch your info regarding bad injector cups until now. That would worry me also, especially if you didn't catch the problem right away. I don't know about the IDM causing solenoids to blow. I do know my buddy got raped for about 2000 bucks when his van needed uvc's and an IDM. He limped home for about 20 miles. His van runs fine now and he had no injector issues after the meltdown.
 
#19 ·
Might have to call Swamp's and upgrade. More money and I ain't got none.
 
#20 · (Edited)
barnbuilder,

It is kind of strange that all of your solenoids are bad? You can replace just the solenoid without having to pull the entire injector. You could swap them with your spare engine's injector solenoids. Also, places like swamps diesel would probably sell just the solenoid. You could still have issues with some injectors but might be worth a shot if your are low on cash.
 
#21 ·
Yes your right I can swap them. I had put three of them in the driverside a while back and didn't notice any difference. Ran that way a while then swapped them back. Dave at Swamp's told me to put a hydraulic pump on the heads to see if the o-rings were leaking and to see if the heads would hold pressure. Just haven't picked up a pump to try it. I probably have a few other issues, or the engine does.
 
#23 ·
Checked it through the UVC. I'm trying to get the house ready for my daughter's engagement party next Friday so I don't have the time to work on the truck. Don't want to tear into it and have it sitting in the driveway when everyone shows up. Nothing like a *******! But thought it could be the UVCG. The connections are dry though.
 
#24 ·
I puled the DS valve cover off to check the injectors. I ohmed them again through the wiring harness and this time they are 2.8-3.0. If the injectors were warm the first time I checked them could that have made a difference? I'm gonna check the passenger side now. I'm confused?
 
#25 ·
I could be wrong, but I think you should check for loose poppets. Otherwise, I think you need injectors--not just the solenoids. My truck needed a full set of injectors with just a few more miles than yours.

If the problem goes away when the truck warms up, then it is more likely the mechanical side of the injector than the electrical side.
 
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