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S15 no power or boost before 4krpm

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Really struggling to find anyone who has had this issue who has posted a solution in the last ten years or so. My car has next to no low end torque or power and boost holds off as the car crawls its way up past 4000rpm then it comes to life on full boost and start hauling ass. I've changed my knock sensor and a whole bunch of vac lines and now I'm looking at possibly changing the turbo gaskets and seeing if the timing is somehow shot. Checked the VCT Solenoid and it seems clean but I'm really struggling to come to grips with what's going on right now.

Anyone got anything they can help with or know of someone who suffered similar issues? Any help would be awesome

Thank you
 
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Is it a stock engine/turbo/ecu? could be a combination of poor mapping and larger turbo, though for something that doesnt spool till 4k would have to be pretty large

dou you have an AFR gauge as that will help to see if its running rich/lean and help to give a better idea of what is going on. Have you checked the plugs for colour and gap?
 
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Hey, nah the car is is completely stock other than a catback exhaust which was on it when it arrived. I don't have any gauges put in as of yet but it does seem to be getting poor mileage and no low down power. It hesitates under pressure when your climbing a hill at low revs too. Now I've searched high and low and check over a lot of components that would have done effect on the performance and economy and my first initial thought was that something is going on with my turbo and I think I've found the answer...

Laaaaaaaaaaag .. Boooooooooost - Page 5

Came across this old three with some others having the same issues except these guys found the answer. So I'm gonna have to find some time to remove the heat shield and see if something is up. If this is the case then I'll be a little pissed since I wondered if it was my wastegate from the get go but a friend of mine (big bad mechanical engineer) claimed it wouldn't make sense...this would not be the first time I've outsmarted him.
 

DeanS15

My car is so clean you could eat off it.
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I would get the base timing checked as that can reduce power across the whole rev range and cause a lot of detonation that you might not notice. Then the usual check for boost leaks, make sure the actuator is good and worst case pull the turbo and check for gasket leaks and cracks around the manifold and exhaust housing coming out from waste gate aperture.
 
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