My brothers 02 wrx has 8k miles on it, when boosting at about 5k rpm the turbo bogs down and it feels like if you were to let off the gas and back on intermittently. It pulsates slowly and the turbo gauge jumps up and down from about .00 to 1 bar, I don't think its a vaccum leak because it boosts just fine until 5k, people have told me its a fuel cut, or overboost, but I'm pretty sure it ain't overboosting.

 

Pull the map off of the ECU.

Is it on the stock TD04?

Who knows what people do with their subarus these days. It's really scaring buy a used one.

 

its completely stock, he hasnt done anything to it.

 

he bought it brand new also.

 

note I said 8k miles not 80k. the car was sitting for about 6 years.

 

Could be a lot of stuff like the fuel pump and or injectors going bad. Take off the intercooler look for tears. Maybe the cat in the uppipe is shot.

So you got a couple choices take it to a shop or problem solve yourself good luck!

 

If it sat for six years, you've probably got cracks and issues with nearly every gasket and hose in the vehicle. Our Legacy GT wagon sat for two years, and had cracked CV boots, head gasket, valve cover gasket, radiator hoses and vacuum line issues. Anything that is used to having grease in it or fluid in it or being under pressure/vacuum needs to actually have that movement/fluid/pressure in it on occasion in order to not crack or harden up to sludge. You could have corroded injectors; you could also have coolant or oil sludge in the block, and at high RPMs you're getting a big temp spike. I doubt it is the up-pipe cat, those are made of palladium (non-rusting) and can outlast the car at normal boost. My guess is you have a tear in your air intake path, or a block in the coolant lines to the turbo, or a bad MAF sensor.

 

you should do a compression test...

 

wow, um ya, if it sat for 6 years... ur looking at possible crazy issues...

 

it could be because u threw that BOV on there.....

 

It was doing it before, I let my friend borrow the BPV and put on his BOV lol...

 

is it like the RPMs go up a few hundred, pause, and then go up a few hundred more, and then pause again? Thats what mine did. I don't know what the problem was (car had 19k miles on it when I got it) but getting tuned by Ed fixed it. The Cobb map lessened the problem, but didn't resolve it completely.

 

That's exactly what it does

 

is it an auto tranny or manual? Mine was an auto and the dealership said it "is the tranny protecting itself from the power of the [stock] engine." I called BS on that. When I had it converted to a manual (no more TCM) it still had the same problem. Bottom line is get a good custom tune. I suggest Ed of EQTuning.

 

We had the same problem with an evo last year and there was a boost leak in the innercoolar piping. Might want to check that, but if it was sitting for a lot of years. You could have a lot of problems with it.