2007 BP5 GT - subtle shudder on boost?

[mitSUBishi-guy]

Wondered if anyone would know what might be happening with my GT wagon? 2.0L turbo, 6 speed manual. I've noticed when the engine is under load and coming on boost there's a really subtle shudder or stutter in the power deliver as the motor winds up. It seems to happen in any gear under brisk acceleration and it's fairly subtle.

It's almost as if the tyres or the clutch has slipped just a tiny bit as the car accelerates (yeah it's not the tyres but it gives that sort of feeling - although could it be clutch? The clutch isn't as good as I think it could be). It happens relatively early in the power delivery when boost starts building. Once on full boost there's no problem - she just pulls like a steam train.

But it's puzzling and would like to know if anyone has a good idea what it might be. I imagine it could be all sorts of things - spark plugs, coils, leads, fuel system... but hopefully someone's seen/experienced something similar and can narrow it down for me. The car's NZ new, 3 years old, full service history and 63km. Hoping it's not a pointer to something expensive cos I did pass on the mechanical warranty!!!

[pullmyleg]

For me it was my turbo man, it didn't seem to have play in the bearings but the inlet turbine slightly rubs on the housing. It could also be your tune, is your foot completely on the floor during this build up? i bet you a aftermarket computer solves your problems... but at a high price.. just my input, seems like something hard to diagnose without seeing the car / getting a feel for the vibration.

[Guest]

What fuel are you on? you need someone to throw a scan tool on it and check live data/fuel trims other wise you wont get any where.

[EJ20T]

yep this is a dealership level problem

[mitSUBishi-guy]

 caged said:

What fuel are you on? you need someone to throw a scan tool on it and check live data/fuel trims other wise you wont get any where.

Running 95. Mainly from Shell.

Yeah I guess I'll have to drop it into Wingers for a look-see. Maybe I disconnect the battery first to try and clear the computer before I take it out for a good long run? Maybe won't hurt to try.

[Guest]

 mitSUBishi-guy']

[quote name='caged said:

What fuel are you on? you need someone to throw a scan tool on it and check live data/fuel trims other wise you wont get any where.

/quote]

Running 95. Mainly from Shell.

Yeah I guess I'll have to drop it into Wingers for a look-see. Maybe I disconnect the battery first to try and clear the computer before I take it out for a good long run? Maybe won't hurt to try.

I wouldnt clear the the ecu memory, Its very handy to see what the car has been doing when your trying to diagnose faults.

[Guest]

 mitSUBishi-guy']

[quote name='caged said:

What fuel are you on? you need someone to throw a scan tool on it and check live data/fuel trims other wise you wont get any where.

/quote]

Running 95. Mainly from Shell.

Yeah I guess I'll have to drop it into Wingers for a look-see. Maybe I disconnect the battery first to try and clear the computer before I take it out for a good long run? Maybe won't hurt to try.

Try 98 and see how you go perhaps?