Excessive manifold pressure

[hacky00]

Hello there everybody,

Am new to the forum and hoping someone can help me.
I have a Nreg surf ssr x 3.0,it sounds like it has a blow from the exhaust manifold,when i investigated i couldn't find a leak in manifold/egr etc..but the sound seems to be coming from inlet tract,i took out the sensor on airfilter(air temp) i think..and there is pressure coming out and not vacuum?
I put a vac guage on manifold and it's not pulling any vac.infact slight pressure(this is in tickover) ocassionally the needle would flicker back to 5inches of merc and then back again.did a compression test and got 540 all across the cylinders,but don't know what they should be,could it be sticky inlet valves,can the turbo gunge up and overboost,or egr stick open?? turbo looks very oily not sure if it's from breather though.Had a look under main butterfly and it's got loads of thick gunk in there!! She runs o.k no smoke etc....

thanx andy

[MattF]

You have checked the flexi-pipe from the air filter housing?

[coolsv650]

mine does not show a vaccuum at tickover also. Normally get boost when on the throttle and only get vaccuum when on the overrun with the transmission in lock up.

The thick gunk you talk about is normally from the breather it vents straight into the inlet tract after the air filter.

As for the manifold pressure im lost. Have you tried taking off the breather pipe and seeing if the pressure stops

[hacky00]

Think i've sussed it,theres a small butterfly alongside the main butterfly,if you close the butterfly a little or apply vacuum to the bottom pipe the whooshing noise stops and it ticks over a treat.this is controlled by vac from a solenoid,i put a noid light on the harness to the solenoid and you get a signal on tickover and when you key off and on overun but solenoid not switching any vac through to butterfly unit,what the smaller butterfly for? is it to do with the turbo when you come off the throttle,does it aid the engine to stop to as the butterfly closes on key off. sorry for my ignorance not too mechanical.....

[MattF]

http://www.toyotasurf.asn.au/forum/v...ic.php?t=22338

[hacky00]

Thanks Mattf had a read this morning,nice to actually understand it at last,thanks again....