loss of boost on toyota supra twin turbo

[carloshoug]

Hello,
Jus wondered if anybody could help me, i have a toyota supra twin turbo, and recently ive lost all boost, it was boosting fine and then jus went! ive tried to find a split pipe but have had no luck, if i remove a pipe from the inlet which appears to go to the actuator, it boosts again but not at full pressure, please help as im pretty stuck on this one!

Cheers

Carl

[Shayne109]

maybe a de-laminated hose collapsing under boost reforming when stopped
quite hard to find but gives symptoms like you state.

[carloshoug]

Ok thank you, dnt suppose u would know a way of finding a hose causing the problem?? I guess its probably jus a case of checking every hose one by one?? thanx for ur help though much appreciated,

[sparkyhx]

1 - inlet pipe collapsing - hard to test for
2 - boost leak - piping, intercooler, wastegate not closing properly or weak actuator
can you pressurise (e.g. bike pump) the system to see if there are any leaks
boost leaks are usually accompanied by lots of black smoke and (but not always) lumpy running

3 - collapsed cat/exhaust - I had this and took ages to diagnose - I even changed the turbo

personally from what you are describing I'd go for 1/3