Injector Problems?

APC9199 · **Posted:** Sat Mar 31, 2018 7:04 pm

Well, it looks like my rash of bad luck with this Jeep continues. I have suspected an injector problem for awhile now but haven't had the time or patience to confirm it. I finally bought (much to my dismay) one of those Chinese garbage return flow kits and checked the injectors this weekend. The initial results are not promising.

So the vials are supposed to be 105ml each. I haven't confirmed actual quantitative measurements but from a quick glance it appears to be roughly 58ml, 68ml, 79ml and 63ml for injectors 1 through 4 respectively. Those are pretty wild results in my opinion. Now, this was a COLD test. I need to go get supplies for an oil change so I'll test again at full temp and see what I get. This seems kind of dooming regardless of the conditions though, no?

Now, it is very possible that the injectors have been this way since I bought the Jeep but I am concerned that some of my habits my have contributed to them getting worse. I use Lucas diesel additive at every fill up (or every other, sometimes). When I started having concerns about the injectors I started using Marvel Mystery Oil in the fuel tank because it is considerably more solvent than Lucas, in hopes that it would help clear the injectors. I suspect that it may have done the opposite. After a few weeks of that I noticed really poor mileage and the engine wasn't running right so I changed the fuel filter and drained the old one into a clear pitcher and it was almost brown! The MMO had released so much crud from the system it clogged the filter. I know the OEM filter caught most of it, but there must have been a ton of fines that made it through with that much in the filter itself. While one grain of sand can't dam a river, many millions can, so to speak. This was almost a year ago and things haven't gotten noticeably worse since then so it is tough to say if any of this is true. Just hypothesis. The long and short of all this is that I am highly recommending that anyone who is using or considering using MMO or any other "high-flash" additives, to install the 2-micron fuel filter setup first, and check/change it often. I have the kit sitting in the garage waiting to be installed, which may happen sooner rather than later now, considering my findings and the cost of injectors. As a side note, I usually fill a new filter with Power Service "White", run the engine for about 30 seconds to clear the old fuel out then shut it off for about 30 minutes to let the injectors "soak" in the PS. I have never noticed any positive or negative result from that, but I figured it might come up here as something to try.

So now for the tough part. What are my best options assuming that the hot test comes back with the same result? Most of my reading has concluded that back-flushing diesel injectors doesn't work most of the time and it can't be done at home anyway. I don't have any reliable injector services near me that I know of, just one that has already screwed me once. There are likely tons of them in Phoenix, but I despise that city. This is my daily driver, so I can't ship them off to be tested and wait a week or two for them to return. Is a visit to the dealer in my future? I have heard of (and once had a guy perform) an injector test with the injectors in the vehicle. I assume that was just turning off the injectors in sequence and monitoring the rpm for fluctuations? Is that going to tell me anything the flow test hasn't already? What would you guys do?

flash7210 · **Posted:** Sat Mar 31, 2018 8:01 pm

Run the test again.
Cut the tubes shorter to make them easier to manage if necessary.
Make sure they are all the same length.
Get it all setup to run the test again.
Start the engine and allow fuel to fill up the tubes, then shut off the engine.
Dump the fuel in the vials.
Attach the vials again and run the test again for real.

Your test in the picture isn’t too bad. #3 is the only outlier.
All for will never be exactly the same but should be relatively close.

flash7210 · **Posted:** Sat Mar 31, 2018 8:06 pm

Also,

Any codes?
What’s your fuel rail pressure look like?

I installed a AutoMeter fuel rail pressure gauge to help with fuel system diagnosis.

APC9199 · **Posted:** Sun Apr 01, 2018 1:58 pm

flash7210 wrote:

Also,

Any codes?
What’s your fuel rail pressure look like?

I installed a AutoMeter fuel rail pressure gauge to help with fuel system diagnosis.

No codes. My rail pressure (OBD Fusion for iPhone) is 5,500 to 5,600 at cold idle. I can pretty easily push it up to ~23,000 with medium to heavy throttle while driving. Not sure what is normal there, but that seems about right to me. Oh, I'm also using the Yeti Stage-I tune.

The reason I'm investigating all this is poor mileage, a more "tractor-y" sound especially at idle, and what seems like an out of balance wheel in the front end while driving at 45mph+ even though EVERYTHING has been inspected, repaired or replaced in the front. I am currently driving with the front differential removed, no CV axles and no front prop shaft, relatively new tires that have been balanced on good wheels and rotated a few times and I STILL get a vibration at higher speeds. I also have new engine mounts. All four wheel bearings have been replaced with no change, the rear driveshaft has new greasable u-joints, the rear diff has been rebuilt, the rear axle shafts have been inspected. This has been happening since before I got my lift, so the lift is not the problem. I'm running out of things to try, so I'm down to checking the balance of the engine itself and trying to get the money to afford having the TC replaced. Checking the injectors is the easiest and cheapest thing to do first. I'm imagining a scenario in my head where poor combustion in one or more cylinders could be causing the engine to rock back and forth under load and feel like something is out of balance up front. I'm not really a gearhead to be honest, so maybe this makes no sense? It really doesn't make sense why it would only be at higher speeds, but then I've eliminated almost everything else that it could possibly be. :5SHOTS:

I didn't get a chance to do the hot test yesterday so I am going to go change the oil and do the hot test today. I'm not sure what your technique, running the test twice, is accomplishing? I'm not questioning it, just curious! When I did mine, I was sure to pinch the tubes right at the injector outlet and raise them to drain them into the vials so the quantity in the tubes wasn't a factor. I'll give your method a shot and report back what I get. Thanks!

flash7210 · **Posted:** Sun Apr 01, 2018 2:18 pm

Correct.
Just trying to make sure that fuel in the tubes is all exactly the same amount and not influencing the overall measurement.
I’d rather the tubes already be filled with fuel and the vials empty.

I don’t think the vibration is related to the engine.
If it were, you could reproduce it by mashing the brake pedal, putting it in drive, and revving the engine at about 1500 rpm or so. (All while sitting in your driveway)

Also, your fuel rail pressure seems normal.
What you want to look out for are rapid fluctuations while holding a steady speed and rpm.

APC9199 · **Posted:** Sun Apr 01, 2018 4:05 pm

OK, this seems pretty conclusive...

I'll have to monitor the rail pressure on the highway on my way to work. Is that going to cause problems using the OBDII port while driving for an extended time? I'll also refer back to my original question. It looks pretty obvious that injector #3 is having problems at the very least. I'm working on getting the 2-micron filter installed, but what would you guys do when it comes time to replace an injector?

In regard to the vibration, the only thing I haven't actually replaced (because there is no evidence they need to be) are the rear axle shafts. I may try to see if the local u-pull-it has any decent ones I can grab for cheap. I've been wanting to try to find some good steel wheels for offroad tires anyway, so I can kill two birds there.

Thanks again!

GordnadoCRD · **Posted:** Sun Apr 01, 2018 5:57 pm

If I understood CaptainDean's post from a couple months back, you can order replacement injectors from across the pond, to the exact spec your injector currently is, by using the digital number imprinted on the top of the injector cap. I don't know if they are used or rebuilt.. I have never done this, so perhaps he can pitch in here..

APC9199 · **Posted:** Sun Apr 01, 2018 6:12 pm

GordnadoCRD wrote:

If I understood CaptainDean's post from a couple months back, you can order replacement injectors from across the pond, to the exact spec your injector currently is, by using the digital number imprinted on the top of the injector cap. I don't know if they are used or rebuilt.. I have never done this, so perhaps he can pitch in here..

I've wondered about this and actually mentioned it to VM Specialist when I ordered my head, but they couldn't provide any info without the code you mentioned. I'll make an effort to get some more info from them regarding the condition of their injectors and what they might charge for them. Hopefully others can chime in as well.

WolverineFW · **Posted:** Sun Apr 01, 2018 11:05 pm

If I were you and you are concerned about injector #3, then pull the injector and have a Bosch certified shop test it. The test will confirm if it is bad or not and how far from baseline it might actually be out.

When I had all mine out, I had them tested. All came back equal or better then specified.

Sent from my SM-N910W8 using Tapatalk

GordnadoCRD · **Posted:** Mon Apr 02, 2018 12:54 am

In some cases, if it actually needs to be rebuilt, they will roll the testing fee into the cost of rebuild.

The reason I mentioned VM Specialist is you could order the proper injector, then when it arrives, swap it out in a single evening. No down time for your daily driver, no need to reprogram the ECM.

WWDiesel · **Posted:** Mon Apr 02, 2018 1:17 pm

GordnadoCRD wrote:

In some cases, if it actually needs to be rebuilt, they will roll the testing fee into the cost of rebuild.
The reason I mentioned VM Specialist is you could order the proper injector, then when it arrives, swap it out in a single evening. No down time for your daily driver, no need to reprogram the ECM.

This is my understanding: There is a 6 position alpha/numeric value for each injector that is programmed into your ECM (Engine Computer Module) :roll:

The code programed into the ECM for each injector has to do with the manufacturer's tolerance variation deviation of flow rates as measured and compared to an established design standard? Some call them "Trim Codes".
This is also why if you pull injectors for any reason, they should be marked with some kind of identification tags and returned to the exact same location.

The engine will run without doing this, but if you replace an injector with a different one, it is highly recommended to have the injector(s) reassigned with the correct trim code in the ECM for max performance and efficiency.

from GDE back in 2011 wrote:

The injectors are designed to last the life of the vehicle. This is highly contingent on fuel filtration and no air ingestion in the fuel supply line...
Very rare to have two fail at the same time unless fuel contamination played a part.

GordnadoCRD · **Posted:** Mon Apr 02, 2018 1:49 pm

I may be incorrect, but I understood CaptainDean to say that The VM Specialist in UK asked for the trim code on his failed injector, so they could send him one that matched. I understand the significance of the trim codes, but don't know how many there are. It sounded as if they were able to ..somehow.. ship a replacement of matching trim code.

APC9199 · **Posted:** Wed Apr 04, 2018 9:14 am

Correct, they ask for the code starting in '04...' to try to match them. The response I got was that they have no used or refurb ones, but they do have new ones. They need the "engine serial number" from the front of the timing cover to get the correct ones for your individual engine (not sure why). Their cost minus shipping is "approximately" £254.00 which is roughly $357. Still WAY better than buying them Stateside, and even better than the best pricing I've seen for refurbs. This country is going to price itself out of competition with the rest of the world in every way we possibly can, I guess. I hate to spend the money to get just one injector from them since they have to ship internationally. I would rather buy 4, replace them all and have all 4 old ones refurbished so they can be sold. That is a lot more short term money though...decisions decisions.

flash7210 · **Posted:** Wed Apr 04, 2018 9:20 am

Oregon fuel injection has one for $380

https://oregonfuelinjection.com/product-category/jeep-diesel/2005-2006-2-8-l-jeep-liberty-diesel/

edit:
you can also search ebay for used ones

also check rockauto
https://www.rockauto.com/en/catalog/jeep,2006,liberty,2.8l+l4+diesel+turbocharged,1432225,fuel+&+air,fuel+injector,6224

APC9199 · **Posted:** Wed Apr 04, 2018 5:12 pm

flash7210 wrote:

Oregon fuel injection has one for $380

https://oregonfuelinjection.com/product-category/jeep-diesel/2005-2006-2-8-l-jeep-liberty-diesel/

edit:
you can also search ebay for used ones

also check rockauto
https://www.rockauto.com/en/catalog/jeep,2006,liberty,2.8l+l4+diesel+turbocharged,1432225,fuel+&+air,fuel+injector,6224

O.F.I. was the lowest I had seen. I figured I would use them, but didn't realize RockAuto had them for less. Their reman'd units are about $280 after core return which is pretty good. I'm not sure how re-manufactured units compare to new (which VM sells for about $375). Since our vehicles never had a factory lift pump or filtration better than, what, 10-20 microns?, I wouldn't trust a used injector without some kind of definitive report from a trusted Bosch shop. So, Ebay is out...

I might go with RockAuto for now and just do the one that really needs it. I'm going to be bummed if I change that one and find out that 1,2 and 4 are all 25ml higher than the new one! :roll:

Injector Problems?

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