Understanding VGT Live Data?

[Spudth]

In my 2015, I have a Turbo that was new in December with the City Diesel Actuator.

My symptoms are no or limited exhaust brake and minimal boost maxing out at about 18PSI.

I have looked for signs of a boost leak and have found nothing.

Using my AlfaOBD Scanner, I see what looks like the correct profile For commanded actuator position, but when I monitor the actual position, I see a flat line at 100%.

Does anyone have any ideas or suggestions why this would be happening other than a bad actuator?

The company wants me to take the entire Turbo off and send it back for evaluation which can take up to 2 weeks; this truck is my daily drive, and I'd like to troubleshoot as much as possible before I take this action.

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[AK Bob]

The City Diesel actuator does a self-test on every key cycle.

Can you hear the actuator moving when you go from ignition OFF to RUN?

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[Spudth]

I got next to the actuator and used my remote start.

The actuator made a metallic gear turning sound but didn't seem to be a forward/pause reverse sound I'd expect.

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[AK Bob]

I got next to the actuator and used my remote start.

The actuator made a metallic gear turning sound but didn't seem to be a forward/pause reverse sound I'd expect.

I just performed the same test using my remote start and recorded the sound at the passenger side wheel well.

I can hear two distinct metallic sounds from the actuator, first one (0-100%), a slight pause, then another shorter one back to (0%) followed by approximately 9 seconds of just fuel pump then engine start.

I was unable to attach the sound file here, so I sent you a PM with the file.

Hopefully you can listen to mine and compare them.

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[Spudth]

I downloaded the file, and it has a very similar sound.

I hit my key too many times and was drowned out by the horn.

The sound was similar but not the same.

I don't know if they think there may be a turbo issue too, or instead.

The turbo was new with the actuator.

I wish I had a better idea of what to expect from live data.

All I know is that as the truck warms up, it has little power.

If I travel at speed and smash the pedal down, nothing happens.

It needs to downshift and get over 3000 rpm to get any boost to get going.

I can read turbo RPMs with the ALFAOBD, but I don't know what good numbers are.

I would expect more boost occurring around 2k RPMs.

The turbo setup will come off and go back in about two weeks, and I'll be down for about ten days if I am lucky.

Thanks for the input.

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[AK Bob]

Glad you were able to download the sound file.

At least we know the actuator is getting power, but if you didn’t hear the same sound, it makes me wonder.

Strangely, you do not see any trouble codes.

Assuming AlfaOBD is working correctly, you should be seeing both VGT actual and desired closely following each other.

The 100% actual readings make me think the actuator is not responding to the command from the PCM or is not able to move the vanes.

The lack of boost also indicates the turbo vanes are not moving.

I assume your exhaust brake doesn’t work either.

Very strange, are you working with City Diesel?

Please keep us posted.

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[Spudth]

Everything you said is what I am thinking.

When I originally received it at the end of November, the wires on the actuator were all chewed up from shipping.

I didn't think the turbo would be hurt, so we swapped the actuator.

They were hesitant then even to send me an actuator without seeing the one damaged in shipping.

The exhaust brake says it's working when I have it in tow/haul mode.

It says 40HP, but that may be misleading somehow, and I have to pay more attention to not in tow haul.

I bought the actuator and turbo through DDP, and I have been speaking with Mike there.

He hasn't offered any ideas, but I plan to work on removing the turbo beginning on June 27th, get it back to them, and they will look things over.

They are very hesitant to offer much in the warranty coverage without seeing the items in case of foul play.

I didn't know about ALFAOBD and how easy it was to use it to calibrate an actuator.

I think the city diesel unit has promise.

Maybe I will talk to them tomorrow for ideas.

I hate to have to send it back.

I wish I had an excellent actuator to see if it communicates entirely with the ALFAOBD.

There is always the threat of coolant in the thing. Everything was new, and I put it together carefully, but whoever knows.

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[Spudth]

I have an update on my turbo problem.

When I was checking the wiring, checking the resistance at the actuator pigtail adapter, initially I got an open circuit.

I disconnected and reconnected the pigtail to actuator connection and I got the 120 ohms I told you about.

Well, since then I have not gotten any codes and the truck has been running progressively better.

I still cannot see the actuator position in ALFAobd.

I have seen 22 PSI boost, not the 30 PSI I got when I installed it but it's better.

As for the exhaust brake side.

I get minimal braking when it is fully applied under usual driving conditions but if I do "tow/haul" it shows like 40 hp braking.

I will be towing this weekend and I will see how it reacts then.

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[AK Bob]

I have an update on my turbo problem.

When I was checking the wiring, checking the resistance at the actuator pigtail adapter, initially I got an open circuit.

I disconnected and reconnected the pigtail to actuator connection and I got the 120 ohms I told you about.

Well, since then I have not gotten any codes and the truck has been running progressively better.

I still cannot see the actuator position in ALFAobd.

I have seen 22 PSI boost, not the 30 PSI I got when I installed it but it's better.

As for the exhaust brake side.

I get minimal braking when it is fully applied under usual driving conditions but if I do "tow/haul" it shows like 40 hp braking.

I will be towing this weekend and I will see how it reacts then.

Well, this is encouraging news, not sure why you are unable to see the actual VGT position on AlfaOBD.

It would be nice if you could verify your Alfaodb is reading correctly on another truck.

I had a similar issue with a different program, on my “Autoenginuity” software the VGT actual was reading 0% and didn’t change.

The desired was reading correctly.

They sent me a software revision and then they both worked fine.

Hope all goes well this weekend.

Please keep us posted.

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[Spudth]

That's interesting about Autoenginuity.

I had purchased an older version for use on my 2002 Powerstroke.

It was great for my needs but considerably expensive if I expanded to other brands of cars.

Perhaps I can reinstall AlfaOBD for better luck but it seems to work on every other function.

I will keep posting as I'm not too fond of threads with no follow-ups.

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