7M - Most common area for a Vacuum leak?

[Negative Boost]

Thanks hamgatan! Looking forward for the part number

[WA_TRD_83]

Hey menace..
sorry to take over your thread - but the guys here seem fairly knowledgeable in terms of vacuum/boost leakage..

is there an easy way I can determine where I have a boost leak?

the car hasn't moved the way it should since I did the engine conversion. Its a bit of a concern cos everything is new. all new clamps and new hoses/rubber joins etc..

but the car is overfueling heaps! plenty of black smoke out the exhaust - and foot to the floor only sees about half the power the engine should have and really struggles on boost. (if I drive without boost it drives ok)

boost gauge currently reads 7.5psi.. can't wind it up any more than that, or it hits boost cut?! (which is why i think I must be loosing pressure somewhere along the line)

comments?

could it be my factory BOV is stuck? or stuffed as previously mentioned by Chris?..

Damo
TRD83

[WA_TRD_83]

sometimes the idle goes up and down... like a wave..
not sure if this is to do with the same problem, or a different problem... ?
maybe its an indication of where my leak is?..

ps.. my first turbo car.. so these problems are all new to me!

Damo
TRD83

[wagonist]

Repco (& I'm sure others now too) also sell that BOV as its simply a Bosch item.

[CrUZida]

sometimes the idle goes up and down... like a wave..

It did that when I had it too, I couldn't solve it so I just put it down to the crappy intercooler piping/setup the original owner had done.

For a bit more info on WA_TRD_83's motor, every rubber pipe across the top of the motor has been changed for brand new, the throttle body and ISCV have been cleaned, and the TPS is correctly set.
Injectors have been serviced too.

[ViPeR_NiPPleX]

faulty wastegate actuator?

[JustCallMeOrlando]

Was the intercooler you bought new or second hand? It definetly sounds like a boost leak of some description. All in all, the easiest way I found to locate leaks was the old vacuum hose in the ear trick going around the bay, following every part and in particular looking at every join.

[CrUZida]

faulty wastegate actuator?

The turbo is wotthe?'s old super hi-flowed jobbie.

[WA_TRD_83]

faulty wastegate actuator?

I dunno if you are on to something there.. ?

it was running 5psi (according to boost gauge). fit bleed valve (even on minimal setting ie, should make no difference) it goes up the 7.5psi on the boost guage.
remove bleed valve and install factory hose again - we have 5psi ...

does this mean anything?

[WA_TRD_83]

The turbo is wotthe?'s old super hi-flowed jobbie.

yeah.. thats the other thing...
its basically a brand new turbo... was rebuilt and only used for a few months on Matt's car.. so I would hope that everything to do with the actual turbo functions correctly..

[WA_TRD_83]

I'll also add that currently one of the knock sensors is not hooked up too..

don't seem to think this will make much diffrence... but with the ECU detecting an error all the time - would this restrain power in anyway?

Peewee.. is this something Matty could hook up while you are away?

Damo
TRD83

[CrUZida]

Sure Matty can hook it up, the wire stopped somewhere near injector #6 from memory.

But wotthe?'s old 7MGTE Soarer has the same problem (knock error) and that MZ20 still pulled a 13.9 @ 14psi.

[WA_TRD_83]

Was the intercooler you bought new or second hand? It definetly sounds like a boost leak of some description. All in all, the easiest way I found to locate leaks was the old vacuum hose in the ear trick going around the bay, following every part and in particular looking at every join.

Intercooler is second hand..
could there be something wrong with it?..

I was there putting the piping together too.. we sealed that stuff good and proper.. so hopefully there's no leaks from the cooler piping?
unless its been cracked or damaged recently

Damo

[JustCallMeOrlando]

It could have a leak from the core itself. Wouldn't be the first time.

I doubt the bleed valve shuts all the way, hence it makes a small leak right from the get go, accounting for the higher boost.

[WA_TRD_83]

It could have a leak from the core itself. Wouldn't be the first time.

I doubt the bleed valve shuts all the way, hence it makes a small leak right from the get go, accounting for the higher boost.

is there a way to test the cooler?
or just stick another one in there and see if it makes a difference?

Also - should I remove the bleed valve then? and just work on getting to standard boost from the current 5psi I'm getting.. ?