[N88ufo]

Hi, my GT has today started playing up, I've done the usual searches but have not yet found a similar problem, under full throttle I'm only getting about 3/4 boost before it starts to shudder and loose power, drives fine upto that point, its done 80k and has a full service history, I'm hoping someone else has had this issue and can tell me the problem.
Thanks

 

[Captain America]

Hi, my GT has today started playing up, I've done the usual searches but have not yet found a similar problem, under full throttle I'm only getting about 3/4 boost before it starts to shudder and loose power, drives fine upto that point, its done 80k and has a full service history, I'm hoping someone else has had this issue and can tell me the problem.
Thanks

Does the engine malfunction light come on. Are there any split or loose air intake hoses. Petrol or diesel. Any loose corroded or chaffed wires connected to the turbo housing.

 

[N88ufo]

Thanks, it's the petrol gt, no engine light and damaged wires or pipes I can see, I'm stumped

 

[Dubs]

Fault code scan.
Not every issue puts the light on.
Live data views of boost pressure requested vs actual, Ignition and fuel trims etc.

Checked every boost pipe hose for splits/holes... They aren't always easy to spot.

 

[Captain America]

Thanks, it's the petrol gt, no engine light and damaged wires or pipes I can see, I'm stumped

Maybe a restriction in dpf or cat? There are products like Fortè that go in the tank and clean the turbo. Can you remove a pipe to the turbo and look inside for build up of carbon and see if turbine spins freely.

 

[Stravs]

When was the last time the fuel filter was changed? I had similar symptoms when my fuel pump went bad... I'm not saying it's the fuel pump but if the filter hasn't been changed in a while then it could be clogged resulting in fuel starvation when asking for more power, and as the fuel filter is located in the fuel pump assembly inside the tank they often get missed/ignored.
Have you checked it for codes too? I've had engine codes on mine even though there was no light on the dash.

Also be sure to check check and triple check the wires to sensors etc whilst using a multimeter, I was chasing a problem with mine for months (not even Kia) found the issue... long story short a camshaft position sensor wire had broken but wasn't visible to the eye, the actual copper core inside had broke but the outer rubber was still intact.

 

[N88ufo]

Thanks for your reply, I've scanned for codes with Delphi diagnostics but nothing, I've bought a new set of plugs and a new fuel filter, will try these and see what happens, would you have any advice as to changing the fuel filter, as sounds far from straight forward, thanks again

 

[Stravs]

Changing the fuel filter can be fiddly, just take your time and be careful not to break the plastic clips that hold the fuel pump assembly together but all in all it's a simple job.
I'd also recommend doing this when the fuel tank is low on fuel because I found it tricky holding the fuel pump in place when trying to bolt in back in due to it floating on the fuel (like trying to hold a bottle under water)

I just followed the steps in this video pretty much and everything went fine.
Replacing the Fuel Pump and Fuel Filter on a 2014 Kia Forte - YouTube