2JZ-GTE Boosting Issues

[BMWTurbo]

I found that if you 'feed' the throttle on say 50%-90% gradually you might be able to sneak out boost spikes and keep it under the 'cut'.

I just rechecked my cap and it's 4.3volts, so you shouldn't have any issues these.

Could be the early rev limit(5000ish), easiest solution for that is to fit a supra ecu Pretty sure the Check light doesn't come on with this however (has been a fair while since I sorted that one out )


Pays to replace all vacuum/boost lines in the turbo system. for the $15 worth of pipe it will cost you and a handfull of zip ties, cheap insurance.

[wilbo666]

I found that if you 'feed' the throttle on say 50%-90% gradually you might be able to sneak out boost spikes and keep it under the 'cut'.

I just rechecked my cap and it's 4.3volts, so you shouldn't have any issues these.

Could be the early rev limit(5000ish), easiest solution for that is to fit a supra ecu Pretty sure the Check light doesn't come on with this however (has been a fair while since I sorted that one out )


Pays to replace all vacuum/boost lines in the turbo system. for the $15 worth of pipe it will cost you and a handfull of zip ties, cheap insurance.

I've had the whole turbo system apart so all the hoses are OK. (I got the engine sans turbos)

Yeah, I think it might be the early rev limit thing after talking to brett... I've got a blitz ecu on the way apparently so will see how that acts...



Cheers
Wilbo

[BMWTurbo]

Try D/Cing the TPS and going for a strap... If it works fine, then it's the early rev limit...

[wilbo666]

Sweet, that sound like an easy way to test

Cheers
Wilbo

[PlacentaJuan]

The thing is it isn't at the limiter....

Cheers
Wilbo

fake rev limit hits at about half the maximum revs; i tohught it was boost cut for a while but if you forget all about boost and accept that it can happen it is exactly like the car is hitting rev limiter (bouncing)

a few people have had this problem using an aristo engine + ecu into a lighter car.

the best fix has been to use a jza80 ecu.

you can test this by pulling the TPS sensor plug and flooring it, while it wont change gears you should still see good acceleration in first gear without the cut happening, if you dont get the cut with tps removed, get a supra ecu.

[Esteban]

That's awesome news! And wilbo doesn't need the aircon anyway (apparently JZA80 ECU into JZS147 breaks the aircon)

I did mean to try this, but the ECU I bought was a fake! It's a non-turbo POS so I can't test the aircon theory or lend it to you wilbo :-(

We still need to drink beer however.

[brett_celicacoupe]

That's awesome news! And wilbo doesn't need the aircon anyway (apparently JZA80 ECU into JZS147 breaks the aircon)

I did mean to try this, but the ECU I bought was a fake! It's a non-turbo POS so I can't test the aircon theory or lend it to you wilbo :-(

We still need to drink beer however.

depends how you wire it..... my ac bypasses the ECU altogether.


idle up-smidle up, its not that much load

[wilbo666]

Well I have a few options to go on now!

In my hands I have a blitz acess ecu...so that is one thing I can try!

Another is discon TPS, and another is unground NSW wire it seems...

Also I've wires the AC on/off signal to the ECU so it will idle up, but I haven't wire it so that the ECU controls the AC comp...and my AC isn't hooked up yet either

Cheers
Wilbo

[cambelt]

So yr the ebay king that paid the 500 for that ecu.
dave

[wilbo666]

So yr the ebay king that paid the 500 for that ecu.
dave

No....are you kidding me! (bwahahah!)

That person got ripped in my books

Cheers
Wilbo

[wilbo666]

I'm still having issues...

Seq


TTC



The Seq graph is way different to the above one...



Something is wrong with my system...

Initial boost is crap!

The first thing that comes to mind is checking the prespool valve on the rear turbo isn't constantly open...

Cheers
Wilbo

[PlacentaJuan]

sure its not the rev limiter?

do you have a supra ecu yet?

[brett_celicacoupe]

i was thinking and i think you should check all the solenoid valves are connected the correct way.

also check the pressure in the resivor

[PlacentaJuan]

^ yea cambelt knows how to reco the solenoids so they operate better

[wilbo666]

sure its not the rev limiter?

do you have a supra ecu yet?

I no longer have the fake limiter issue.

I have a blitz ECU (ex JZS147 I believe).


Pressure in the res is fine. I hear pressure release if I pull the IACV hose etc. I can also hear the exhaust note change (get louder) if I flick my TTC switch while driving along not in boost. So that means the pressure system and the EGBV works.


The front turbo wastegate VSV is def connected correctly. And I quite sure the others are too, but it is something to double check...


I've got some things to check...(again)
IACV: If this was leaking, then the front turbo air would go back out the compressor to atmosphere...

Prespool System: If this was stuck open then it would be kinda like having the wastegate on the front turbo open while trying to spool it...

And everything else

Cheers
Wilbo