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K04 Boost Control Issue

peter22

New member
So long story short:
- Took a car to a dealer because of boost issues.
- Dealership told me my wastegate was sticking and I need a new turbo.
- Decided to upgrade to K04 and still have the same issue.

Doing some research online I found that wgdc is responsible for building boost. Checked my logs and I saw that my wgdc was basically 0 throughout the whole rpm range except the WOT run.

3rd Gear WOT:
https://datazap.me/u/peter221/log-1648045293?log=0&data=6-27-44
4th Gear regular acceleration:
https://datazap.me/u/peter221/log-1648045293?log=0&data=6-27-44

My tuner is stratified. I'm still waiting on the response from my tuner but was just wondering what could be the cause of low wgdc?
 

BudgetPhoenix

Autocross Champion
What is the problem exactly you're experiencing? The N75 controls the duty cycle but you would have changed that when you installed the k04 because they are attached to the side of the turbo. It should be near 0 when you're not under load because you are not building boost.
 

GIACUser

Master Wallet Mechanic
Charge air requested vs delivered during 3rd or 4th gear pull?
 

GIACUser

Master Wallet Mechanic
Dealership diagnosed issue, gave you a price on a fix and failed to deliver. You should not have to pay for work you didn’t need.
 

Grabbit

Go Kart Champion
First two links are the same BTW. Actual boost is way below requested. Have you checked for boost leaks? ECU will pull wgdc if it sees such a big delta.
 

peter22

New member
First two links are the same BTW. Actual boost is way below requested. Have you checked for boost leaks? ECU will pull wgdc if it sees such a big delta.
I did. It holds pressure just fine. Could it be a bad MAF or MAP sensor?
 

Grabbit

Go Kart Champion
I did. It holds pressure just fine. Could it be a bad MAF or MAP sensor?

Checking your MAP would be a good idea since it could be gunked up with oil. Not entirely sure on the MAF. It looks like its reporting normally in the logs but I'm no expert. Anything back from your tuner?
 

peter22

New member
Checking your MAP would be a good idea since it could be gunked up with oil. Not entirely sure on the MAF. It looks like its reporting normally in the logs but I'm no expert. Anything back from your tuner?
I sent him my logs on the 23rd. I heard the turnaround time is approximately 2 weeks so I'm still waiting.
 

peter22

New member
Ok, so I actually found out the culprit of my issue was the tune. To be more specific, whenever I flash my car using the accessport (I already tried two different ones) the car loses a lot of its power. I found this out recently when I got my car back from a shop due to a check engine light. The accessport was already uninstalled for a couple of weeks however nothing changed until I got my car back from them. I don't know exactly what they did but the codes were cleared once I got my car back. I could feel the car boosting again and it felt much faster than when I had the k04 on w/ the custom tune from stratified.

I was already planning on trading the car in so I decided to convert it back to stock and sell the parts. After the shop put back the stock turbo on, I had the CEL come up because one of the vacuum lines was disconnected. After they checked it and cleared the codes, the car was basically a night and day difference.

I decided to order a new accessport to check if the one I had was faulty or not, however, once I flashed the car with the new accessport the car felt like shit again. It seems like, for some reason, my car is incompatible with the cobb accessport. Does anyone have any ideas what it could be?
 

GolNat

Autocross Champion
Get a tune from APR or Unitronic. They usually have trial periods For 30 days.
 

GolNat

Autocross Champion
Just to check if the problem is specific to cobb? Because I eventually want to run a stratified pro tune that I already paid for.

Yeah.
 
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