NAN777

guys,

need some idea.. i've checked the FAQ.. basically found a few things that might lead to my problem...

here's the problem:

observation 1
primary turbo runs fine without any issue boosting at 0.85 Bar
when both turbos are running (4.5K RPM above), the boost pattern is dips a little as usual but the turbo does not climb back up to 0.85 bar.. only remained fluctuating at 0.6 bar to 0.7 bar...

this had never happen to me before

observation 2
after the 2nd turbo kicks in... and shifts gear up from 2nd to 3rd...
the boost behaves like this...
"0.6 ~ 0.7 bar fluctuation" full boost --> -0.5 bar (gear change) --> 0.3 bar climbing up to 0.85 bar slowly (RPM around 3K).
in other word... when i shift up.. but RPM is below the 4K mark... the boost pressure does not climb up like usual fast...

these 2 happen the same time...

i've checked the trouble shooting site etc.. found out that i can suspect there are some valves are not closing when dropping below 4K RPM causing the primary turbo to spool and leaked all the way out..

1) the CHARGE CONTROL SOLENOID or ACTUATOR allowing the pressure to leak through the 2nd turbo when it's not closed or stucked

2) the WASTEGATE CONTROL or ACTUATOR.. the pressure all leaked out when the wastegate is stucked open.

but why only 2nd turbo ?

bryant

i would say start cheap. check and or change the solenoids in the rats nest.

NAN777

it's the wastegate solenoid....
replaced it with a boost controller.. fixed all my problem..

RX7Crazy_84

iTrader: (1)

have similer issues but i have mbc rather then ebc

RX7Crazy_84

iTrader: (1)

oh ya but i am non seq dont know where to start anymore

CantGoStraight

Your kidding right ?.....

dgeesaman

iTrader: (7)

If you have nonsequential and it's not working, you simply need to check everything per the diagram you used. Make sure all the doors that were welded or wired shut are still securely shut. Aside from the advice on boost leaks, the 'boost troubleshooting' sites are for sequential issues only.

There is no point where the primary runs alone. There is no point where the 2ndary kicks in. You shouldn't have a charge control solenoid.
There is no boost pattern, except to say what your full boost is and how quickly you can get there.

RX7Crazy_84

iTrader: (1)

well what i mean is i checked almost everything on the car and it looks good and doesnt seem to be leakin boost from anywhere. only thing i have to check is wires and see if everything is still securely shut.