Scoping Injectors . Volvo D11, D13, D16

Christopher Technician Saskatchewan Posted   Latest   Edited  
Unsolved
Heavy Duty
2008 Volvo VNL 16.1L (D16)
Rough Running, Intermittent, No Codes

I am recent to sign up so this message may not be quite set up correctly, and I should have a bit more info with specific test figures tomorrow but have a fairly simple question to start out. Wondering if anyone out there has scoped NCV or SV injector coil voltage patterns. The unit in question is a 2008 Volvo VNL with a D16 , full US07 emissions still equipped. We have a concern of rough running when warm. I took some quick shots with a uscope to start with and planning to get some better shots with a better scope when available. I will attach what I found. All coil resistance check out good 2.0ohms - 2.6 ohms, checked cold and hot. Screen shot of balance rates are attached, not a fault limit, but indicating cyl 1 and 6 are suspicious . Relative compression test, VGT, and EGR function check out good . 5v supply stable at all sensors, Power and ground feeds to ECM test out good at battery voltage, and can carry a 4 amp bulb.... Mostly inquiring to see if anyone has scoped these injectors, and possibly have a known good. ... Listed in the photos below is starting out with cyl 1-6 NCV coil, and then cyl 1-6 SV coil . I noted cylinder 1 NCV to be the odd one out in regards to formation, but need to really go off a known good to know. 

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Michael Mobile Technician
Utah
Michael Default
 

Hi Christopher, Some of those pintle humps are out of place. It seems that the injector coils are not discharging fast enough. The screenshot 7 looks the most textbook to me.

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Christopher Technician
Saskatchewan
Christopher Default
 

Thanks a lot for the input. I am hoping to try to get a known good from a same emission model engine today.

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Chris Diagnostician
New York
Chris Default
 

Agreed with Christopher, 1-6 appears to be sticking to me. also, your control seems to being going below 0. check your ground connections at the scope. If all good, load your grounds.

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Christopher Technician
Saskatchewan
Christopher Default
 

Yes I did see the dropping ground lines, The grounds used were the internal feeds to injectors thru known good banana jack leads and breakout board as outlined in the Volvo test procedure. Unfortunately just could not capture it all on the uscope screen but with moving the screen down I did note that there is a definite bottom found, Not sure if this is intentional on the part of the ECM…

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Michael Diagnostician
Illinois
Michael Default
 

Hi Christopher I have experience with these injectors. Just to clarify here when you did these captures ncv voltage captures each pic is of cylinders 123456 for the ncv coil and the sv coil correct? Also did you take all these captures at idle?

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Christopher Technician
Saskatchewan
Christopher Default
   

Thank you very much for the reply Michael. I have seen many of your videos, including the earlier ones, and would count them as helping to push me into starting to get more in-depth with with electronic diagnosis with some of these problems, it's definitely something our industry is lacking, really appreciate the input.... All captures were taken with the idle set at 800 rpm using the PTO 0…

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Michael Diagnostician
Illinois
Michael Default
 

Do you have a multi trace scope? I want to see Injector Current of the NCV and the SV. Find a common feed or ground for them and put your amp clamp there so we can see all the current ramps. Then we can go from there. Plus I will search my files and show you what I have. Need to do a little homework. Do the captures and let me know.

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Michael Diagnostician
Illinois
Michael Default
 

Also just have the engine idle with no pto on. From my experience the sv coils should not fire at idle but this engine might be a little different than to what I have see on the DD engines. So I'm curious if this might be a issue or not.

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Christopher Technician
Saskatchewan
Christopher Default
   

Sounds good, thanks a lot for the input. The injectors on the Volvo D13 and D16 use wiring with 2 common feeds, having one for the front Bank of 1-3, and a second for the rear bank 4-6. Then individual control circuits for each coil with all wiring being fed from the ECM, both the NCV , and SV are wired in this way. I have checked for both power and ground at all terminals at the injectors with…

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Christopher Technician
Saskatchewan
Christopher Default
 

Was not able to proceed with the mechanical inspection of the top end or the amp ramping of the NVC coils, as customer has placed the job on hold as of now due to cost restrictions. Hoping to get to get back and to the bottom of this one soon to..... But did have an interesting additional development: We had another similar unit in today and was able to review the same test procedures on the…

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Michael Diagnostician
Illinois
Michael Default
 

Hi Chris. I looked through my captures and they are on a DD 13. All I have is current with crank and cam. But by your captures they look like sticking injectors. I would scope the rail pressure sensor also while you are looking at the injectors. This can help id the malfunctioning injector.

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Christopher Technician
Saskatchewan
Christopher Default
 

Yes I also have a hunch on the sticky injectors, I have seen similiar engine running conditions and I have heard unconfirmed rumers it is often caused by premature needle wear, which can result in erratic pintle action and therefore spray pattern. This particular unit has gone thru multiple injector replacements so lead to trying to establish evidence with a scope capture to try and "prove it"…

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Christopher Technician
Saskatchewan
Christopher Default
   

Was able to get a better capture today with the Verus. This is on a US10 model D16 not the US07 as earlier, so this would be SCR emissions equipped but the base engine has not changed. This is my second known good D16 NCV capture that showed a consistent placement of the pintle hump to be even among the 6 cylinders. This is just 3 I uploaded to usb but they were all the same. I think this would…

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Michael Diagnostician
Illinois
Michael Default
 

Their is a difference so yes you have proved their is an injector issue. How did you hook up to the injector? Did you put your leads on pos and neg of the injector?

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Christopher Technician
Saskatchewan
Christopher Default
 

Yes I hooked direct to the injector wiring itself with both scope leads, OEM schematics I went over dont label either coil with negative or positive designations so it was a bit of a trial and error to get a waveform... I have the luxury of bannana jack pinout boxes at the dealership for the EMS and the Injector so that made this fairly simple and easy. The captures posted were taken using…

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