maximp

I have put a new rebuilt engine in my classic sti and a second hand turbo on it but when I put my foot down hard and it spools up (seems quite tame compared to before engine failed) it makes what feels or seems like a thud and looses the revs! It's only done this twice but then I don't generaly leather it.
I thought that maybe it was overboosting but it's boosting at less than 1 bar, is that correct?
Before the crank went on the old engine it all ran fine and I only replaced the turbo as I didn't want to put anything back on the new build that had contaminated oil through it. So basicly the only thing that's changed is the turbo. I have read that maybe it's the actuator? or that the boost solenoid has been clogged?
Any ideas please chaps

scoobyride

iTrader: (8)

r u sure is not in limpmode this causes the car to not rev over 3500rpm when u do over rev that u will get a thud as you hit fuel saftey cut the car obviousley isnt coming on to boost either is it? somebody with more knowledge will be along soon. best to describe what turbo u fitted and also what ecu you are running in your car as this will enable every1 to help you out fully

maximp

It was at about 3.5k revs in third gear the 1st time it did it and the 2nd time I was in 5th and going some so not sure what revs it was at then!
Whats limpmode?
Duno whether it's boosting correctly or not that's why I asked as i don't know what it should boost at. It does like I say not seem like the animal it once was
Td05 turbo and the ecu is the standard jap sti one, 4 plug. car 1996 if that helps

maximp

Should it be higher than 0.9bar? What about a manual boost controler I hear they can help??

Ciaran

iTrader: (16)

Is the car mapped for the turbo or is it the same type?
I would imagine it should be about 1.2 bar standard but I may be wrong.

maximp

It's standard ecu and turbo for the car.

scoobyride

iTrader: (8)

if ur car is boosting 0.9bar then ur not in limpmode the standard boost for an sti is 1.1bar depending on the ecu you have! have you checked all vacumm hose's? boost pipe running from the intercooler? also are you running a dumpvalve? if any of these are loose or not fitted correctly then you will lose boost

maximp

Standard dump valve.
It makes a loud hissing when iddling from around the solenoid area but cant see any pipes off.
The pipe with the pill in it is not conected to anything and there are 2 others blanked of as it's got an induction kit fitted.

scoobyride

iTrader: (8)

that pipe with the pill in it should be connected to what im noy 100% sure but i will find out this may be ur problem you are loosing boost via this