Boost gone bye bye.

[Quint]

I've recently lost 3 PSI from my supra, ran a diag and it came up clean.

Would a boost leak cause a consistant loss? Or would it fluctuate?

Do i need to start replacing plumbing and intercooler (might as well if i'm changing shit around) or is there some other niggling thing i should check out before shelling out $$?

[Silent Knight]

Do you actually feel a difference in performance?
Try using another boost gauge just to make sure that your one is not stuffed...

[flygt4]

boost leaks can cause all sorts of weird shit. when i had a leak that blew my turbo, it was running 9psi instead of 15psi, but the actualy turbo itself was screaming away pretty much freeboosting to maintain that pressure.

so if you only have a slight leak you may only lose a couple of psi through it, and you'll end up a few short.
sometimes itll fluctuate too, and often the boost response will feel dampened a bit.

id be inclined to take the time to pull the whole piping system to bits and check for leaks,splits, clamps not done up etc . after all it is free

other possibility is you could be having a actuator issue or something.

[big_boy]

if your good mates with any one with an utra sonic tester take it to them & get them to wave that arround in there to see if you can pick up any leaks that way

[Quint]

Do you actually feel a difference in performance?

Huge differance. Runs about as quick as my brothers celica now, which is upsetting.
Looked at all the pipeing seems to be unsplit and in good order etc.
I hope its not eletronic, i hate electrics >_<

[sergei]

if you dont find any leaks It could be cracked turbo housing (wastegate seat area) or the turbo itself (sludged/semi-siezed bearings)... Or something simple like leaky BOV (if you have one) you would not even spot the leaky BOV from outside (if it is factory/or aftermarket return type)...