13' with 17' turbo, low boost when cold

Dzchey21 · Jan 24, 2019

Please read entirely

I have a 13 Superduty with a 17 style turbo upgrade. The truck will sometimes be unresponsive at temperatures under 20 degrees outside. Sometimes it will happen right at start up, other times it will take some driving. Generally when it does happen its when you sit at a stop light for about a minute. The VGT duty cycle will go to 12.16% and stay there until you do a key cycle.

MAP, EBP, BARO are all reading correctly. MAP sensor has been replaced.

I messed around and tried to duplicate the issue by applying pressure to sensors, unhooking sensors ect. The only way i can make the vanes go to 12.16% is by unhooking the MAP sensor. However when I unplug the sensor, and plug it back in, the truck will run fine. It does not take a key cycle like the actual issue I am having.

The truck is Tyrant tuned, I have Reached out to Cale but i am not convinced its a tuning issue.

any ideas would be appreciated,

Thanks,

sootie · Jan 24, 2019

What air intake is on the truck and what tuning platform?

Reason i ask: I did a 17 retro on a 13 and ran into the same issue. Same vgt % and everything. Would randomly have no response and smoke. Was running a No Limit stage 2 intake. H&S tunes by a reputable tuner, apparently for a 5" dia intake tube. Truck didnt respond well under 1800 rpm at all. Ran fine at WOT.

Went into the tunes and put a bottom hard limit of 25% on the vgt cycle. Minimized the issue but it didn't go away. Ran a stock MAF table and the truck ran great, just lacked power. Started gradually changing the MAF scale until we were happy with performance. When we got it right, we never saw 12.16 or 25% again when we were monitoring. It was simply a MAF scaling issue.

So, first check to see that your MAF is clean and in the tube the right way. Then, if you are running a larger than stock diameter intake, swap the stock intake on and see if it goes away.

Dzchey21 · Jan 24, 2019

Was your acting up all the time? This truck drives great every day. When the ambient temp falls then thats when we have issues. It does have an aftermarket intake, i will see if he has the stock intake.

Thanks,

sootie · Jan 24, 2019

Dzchey21 said:
Was your acting up all the time? This truck drives great every day. When the ambient temp falls then thats when we have issues. It does have an aftermarket intake, i will see if he has the stock intake.

Thanks,

Not all the time. But it was middle of winter up here lol

Couldn't tell you how cold but my fingers were numb trying to use FORScan on the laptop while diagnosing haha

Dzchey21 · Jan 25, 2019

sootie said:
Not all the time. But it was middle of winter up here lol

Couldn't tell you how cold but my fingers were numb trying to use FORScan on the laptop while diagnosing haha

so probably similar. I went and got a stock intake last night, but the tuner sent me some different files to try and so far so good so we are going to stick with that. I think when this symptom would happen it was when the vanes on the turbo would cycle like they normally do, they just never recovered from going wide open.

I'll keep you posted, next few days its supposed to be cold so we should have some good testing.

sootie · Jan 25, 2019

interested in what he changed in the files...

Dzchey21 · Jan 26, 2019

I agree with that, I am unsure. It did appear that the file only goes to 25% now at the lowest. The other thing I noticed is that when you are sitting there at idle the vanes do not open and close periodically. That is when the truck seemed to act up. I don't know if there is a self check during that process for boost response? Odd issue for sure

dsmracing1 · Feb 1, 2019

A lot of people seem to be having this issue in cold weather, myself included... In for results as I have the turbo upgrade on my 14 with the NL stage 2 as well.

sootie · Feb 2, 2019

dsmracing1 said:
A lot of people seem to be having this issue in cold weather, myself included... In for results as I have the turbo upgrade on my 14 with the NL stage 2 as well.

With proven diesel tunes as well?

dsmracing1 · Feb 2, 2019

sootie said:
With proven diesel tunes as well?

Yeah. I’m not worried as I’m moving to BC here soon where the trucks runs flawless with his tunes since the weather doesn’t get cold anyways haha.

dsmracing1 · Mar 21, 2019

dsmracing1 said:
Yeah. I’m not worried as I’m moving to BC here soon where the trucks runs flawless with his tunes since the weather doesn’t get cold anyways haha.

Got new updates and it’s since been fixed. Tunes are flawless!

sootie · Mar 21, 2019

dsmracing1 said:
Got new updates and it’s since been fixed. Tunes are flawless!

What did they change? And what temp did you test it in?

dsmracing1 · Mar 21, 2019

sootie said:
What did they change? And what temp did you test it in?

Variations of temperatures really. It tended to happen from changes above and below freezing and has since not done it with his new updates. As far as what exactly he changed, I’m not 100% sure but she’s running better than ever! I’m thinking MAF and VGT areas are what he was tweaking.