Injector efficiency test?

[steved]

Since I have been unable to resolve my issues (which seem a lot like injectors to me), I was thinking about contacting the local dodge dealer and having them scan the computer and run the injector efficiency test to see if that is/isn't the issue.



My only reserve is the fact these are modified aftermarket injectors... will that make a difference since only the nozzle changed (the electronics should be the same)??

 

[AH64ID]

I don't think the DRB could tell... But if anything the duration will be lower based on slightly more fuel from the modded tip.

 

[lmills]

Steve, stock or modded does not matter. Let me know what you find out if you go that route

 

[steved]

Lloyd:



Will do... might see if I can get it in next week. Probably just have them test it in the parking lot.

 

[AllianceDiesel]

If I remember right you can't find that information on the drb, only on the starscan and your truck is too old for the star scan, and from what I have heard the "effiency" isn't really accurate

 

[steved]

Anyway you could verify that before I waste the effort and $$?

 

[AllianceDiesel]

let me make a call to my buddy who is a tech and see if he knows, or you could call the dealership and talk to the diesel tech, I havn't looked at a scan tool in over a year so my memory is starting to get scetchy

 

[steved]

Thanks...



I don't think they actually have a specific tech for the CTD around here... so I doubt they would know...

 

[MA2LA]

if they don't have a dedicated tech for CTD it will proble be a waste of money

 

[AllianceDiesel]

I didn't get a chance to call my buddy, I will defenitely try tomorrow, and I agree if there isn't a tech that knows what he is looking for, you will have a better chance, and like I said, I don't think its an accurate test, I tried it once and I told the star center my results and if I remember right they said don't even try running it.



I will do some calling tomorrow, sorry trying to get my garage drywalled.

 

[Bob4x4]

That test is not real accurate,you might want to purchase some special tools from miller and check return volume instead.



Bob

 

[AllianceDiesel]

hehe, I might have a set of those tools that magically found their way into my tool box.



I called him today and no answer, try to see if you can get the injector return special tool and the cap off tool also.

 

[steved]

That test is not real accurate,you might want to purchase some special tools from miller and check return volume instead.



Bob

I'm not worried so much to the mechanical portion of the injector (the tips, popit ball, etc) as I am the electronic portion of the injectors (the solenoid).



I have no doubt the Flux 1 nozzles are fine, but they were placed onto my bodies. And I think that one of my injectors is failing electrically and was hoping to see it with a efficiency test.



I had a miss this AM when I started the truck after driving it 300 miles home for the holiday. It loped, missed, and smoked like a freight train for a few minutes... unfortunately, I did not have my camera with me to document the event. You can almost see everytime the culprit hits because it gives a puff. It cleared up after a few minutes...

 

[steved]

hehe, I might have a set of those tools that magically found their way into my tool box.



I called him today and no answer, try to see if you can get the injector return special tool and the cap off tool also.

I have a rail pressure guage, 6kpsi at idle and 17500psi cruising at 65-70mph... those seem very typical for what I have read others reporting for rail pressures. I also read that if the return was too high or the rail pop-off was leaking, I would see lower than normal rail pressures?

 

[AH64ID]

I had a miss this AM when I started the truck after driving it 300 miles home for the holiday. It loped, missed, and smoked like a freight train for a few minutes... unfortunately, I did not have my camera with me to document the event. You can almost see everytime the culprit hits because it gives a puff. It cleared up after a few minutes...

I get a very similar miss, usually after a long day on the road... But I have only seen puffs of smoke once. Personally I think that one of my solenoids is failing to fire the injector... Of course I am under warranty, but it happens so infrequently that the dealership will never be able to diagnose it (4 times in 6 months)...

 

[Wayne M.]

I have an 04. 5, and access to a DRB. I have plugged in and the DRB does do an injector efficency test on the 04. 5. IIRC, all were in the 90-100+% range, so I assume all was well. I didn't have a problem, just poking around.

I do however, notice a real difference when I run LSD instead of ULSD. Sometimes I'll get a slightly choppy idle to the point where I'll drag the clutch or rev it up to see if there's a miss and I could never catch one.

Regarding modded injectors, I doubt the pulsewidth would be dependent on nozzle flow. I have always known electronic diesel engine controls to be non- feedback. That thinking would be proper regarding modern Gasoline EFI. It won't be long before Diesel's will be feedback- it's starting with regeneration on the new stuff.

 

[steved]

I have more/less determined I have a weak/failing injector...

When the voltage drops due to the grid heaters turning on, I get a miss... when the grid heaters turn off, the miss goes away. Which leads me to believe I have an injector with a weak solenoid.

Now to determine which one... or should I bother with that and just buy a new set?

 

[Wayne M.]

Steve, I would diagnose a bit further. I have seen electrical problems in other vehicles cause problems that are unrelated to each. Are the batteries up to snuff? is the alternator putting out? If any of these is marginal you can bet on problems when a high load circuit energizes. I would look further before I went for a set of injectors. Maybe do a voltage test at the battery with a DVOM while the grids are cycling and let us know. Maybe we can compare notes, of if it goes below 8VDC, let's say, I would go look at other things before injectors.

 

[steved]

I had the batteries and alternator tested not that long ago... the batteries are practically new Deka's and the testing indicated everything in the charging system is fine... they tested the batteries with a 300A load...



The truck starts and runs fine... just stumbles when the grid heaters pull in. Voltage drops to around 12. 2VDC if I remember correctly, when the grid heaters pull in. I will verify tonight...



And it would be more than a single injector if it was a commonality thing? I can only hear a single injector start tapping when the voltage drops. And it taps just like a stuck injector (only not as loud).

 

[steved]

Well,



First dealer: service writer "the service manager says there is no such test"... which I asked, how's your service manager know more than his diesel tech? And hung up the phone.



Second dealer: service manager/writer "not sure if there is such a test, the diesel mechanic here is telling me it is most likely the injection pump like the 01s"... to which I responded its an 04, which is a common rail and CP3, not an 01 with a VP44... " That got me a "call tomorrow around noon and I'll put my senior diesel mechanic on the phone"... I guess he's out today. I did get the "are you sure its not the injection/lift pump"... and when I respond "rail pressure is normal and I have a FASS pushing a solid 15psi to the injection pump", I got a "you need to talk with the diesel mechanic because your beyond me!" I did not tell this guy I actually bought the truck from them... so we will see how it goes tomorrow.



So time will tell... diagnostics is $88/hour, and I told them I would gladly pay them two hours of time to scan the ECM...