Bet you can't solve my problem

[Slickturtle]

Hi Everyone

I haven't been on for ages but I really need help. Just got my JK Sport diesel manual (70,000 klm) back from the dealership in Darwin. After 3 weeks and every conceivable test (including talking to the tech experts in Melbourne) - they have basically given up - can't fix it. To their credit, they have been very good - I even got to spend a lot of one on one time with their Jeep mechanic - who is himself a Wrangler Sport owner.

The car was fine when I put it in my shed in November last year. I was then away for 6 months (over the wet season). When I took it out of the shed in May this year it was malfunctioning. I have been trying to get it fixed ever since May - but no luck so far.

Problem is lack of turbo boost in the mid rev range. The check engine light comes on and car goes into limp mode. Code indicated turbo wastage actuator faulty.
So we fitted a brand new complete Garrett turbo - no change!
Code showed 'under boost' But boost is fine at start up and in 1st and 2nd gears. Also boost is fine if you can get it over 3,000 revs - but it takes a looooong time to get there. But it will then rev out normally and take the car to 130 klms. + (legal limit in NT!)

Other things done by the Darwin Jeep dealer:
• New air flow meter
• Removed exhaust and inspected
• Looked for evidence of rat infestation or chewing. (not uncommon amongst vehicles when left in storage in the NT). But no evidence of rodent tampering found. Nor was any rat debris found under or in the vehicle in the storage shed.
• inspected intercooler pipes and intake hose
• cleaned mass air flow sensor
• cleaned intake temp. sensor
• did map of boost sensor. Found actual values and target values to be different.
• turbo only making boost at higher revs
• smoke test on exhaust and inlet side of motor – all OK
• Contacted Garrett with specs on new turbo – all OK
• On advice from Jeep tech center, disconnected intake pressure sensor – no change


So what to do? The dealership and my local mechanic (who is excellent) suspect it could be electrical. But close inspection of wiring (as best you can) shows nothing and no code comes up.

I love my Wrangler but I don't want it to become a garden ornament!!

Can you help me out with your combined vast experience?

Slickturtle

[projoe]

I'm guessing you tried something as silly as a new battery?

[mike_nofx]

Could it have something to do with the EGR valve?

Its strange how it was fine when you parked it up but now it isn't. It kind of makes me think that its a moving part which could have corroded and seized in place in the 6 months it wasn't being used (I believe the EGR has moving parts) or maybe a vacuum hose which deteriorated and maybe cracked.

[NTRubicon]

Are the turbo hoses flattening while under load? They inspected them but did they try replacing them, or even swapping new hoses in from another vehicle for a test?

[rustynuts]

Old fuel maybe?

[Grippy]

Busted capacitor in the ecu leading to dodgy readings 😎

Sent from my SM-T530 using Aussie Jeep Offroad mobile app

[MightyMouse]

Take it to someone with a chassis dyno and diagnostic gear....... run the thing and watch whats happening to the wastegate servo, Lambda, boost etc.

Trying to diagnose difficult issues like this when stationary or on the road can be very challenging. At least on a chassis dyno you can look and record whats happening.