1GGTE 12 pound boost problem ? i need some help !

[Admiral coFF33]

Hey guys , Merry Xmas !

i got a boost controller and a turbotimer and PSI guage for Xmas

ive installed them all correctly and the car operates fine.

as far as i know 1GGTE gen2 have 9psi stock

but if my 1GGTE goes past ~11psi the car will start to shudder and have a bit of a fit
its as if 2 of the pistons stop working or something i cant explain it !

when installing the boost controller my mate and i thought it was stock leaving the allenkey adjust all the way out , we were wrong and we took it for 2 runs at 18 - 20psi
only short runs because the car did that shuddering thing.

but the engine has done 175.000kms and my gearbox has about a month worth of life left in it

but after the change of 2ndto3rd and everything before the box is fine, so im guessing that isnt the problem

the boost controller is a GFB allenkey manual one that i adjust from the engine bay and is currently on 12psi

what could be the problem and what would be the best thing to do at this stage (i know im taking it easy but who would be able to look at it and tell me the trouble) ?

cheers

[ITS-18T]

That could be the ECU's fuel/boost cut kicking in. I'm not too knowledgable on the 1G-GTE's however, perhaps the problem is related to something else.

[Hydra]

When i've hit the fuel cut, the engine tends to cut the fuel for at least 1 second, more like 2, and then kicks back into action. Mind you this rarely happens - when it does it's extemely cold and has spiked past 15psi high in the rev range.

I'd check ignition, timing, compression etc.. Also make sure you dont have any air leaks

[Admiral coFF33]

there is surely no air leaks , its as if the turbos are shaking or something is getting over revved and comes loose at the 11-13 psi range

its so odd , i think ill have to get some of the more knowledgeable perth toymodders to come take a ride to see what it is .... cruz ? mischeif ?

[Hydra]

Sounds odd

Maybe the excess pressure is creating a leak, either on the intake or exhaust side (before the turbos on the exhaust side).

You shouldn't really hear any air noise, more high pitched whistling from the turbos.

[Matt-AE86]

Its probs your auto john..

[brett_celicacoupe]

ive only hit boost cut once. im running ~15.5psi on a stock gen3 1ggte (cept for unifilter and FMIC). it happened the other night when the motor had only been running for about 3 mins and i gave it a bit. it cut for like one second.....like someone turned the key off and on.

[GTtwin]

A Gen 2 shouldn't have a boost cut. I had similar problems with my Gen 2 powered GZ-20 ages ago. I set the timing to 12 deg advanced, (when I was running a standard cooler) and problem was fixed.

[Hydra]

There isn't a boost cut, there is a fuel cut (Maxxed out AFM).

[Admiral coFF33]

GTtwin , you had the gen2 at 12 pound with just advancing the timing ?

is there any side effects ?

apparently with a FMIC and some fuel line tweakage u can get 1g's to about 20psi

the problem is not boost/fuel cut because the car runs good , but the shuddering is the issue im talking about ...

[GTtwin]

The shuddering occored on mine when I was running stock cooler, 14psi and 10 deg advanced. Before I had a boost guage on it, it was actually running 18psi, (boost set by same turkey that didn't bolt my camshafts in properly). As soon as I put it down to 14psi and took timing to 12 deg it was fine, and went much quicker. This was about 2 1/2 years ago. A bit over a year ago I put the bar and plate cooler in and took the timing to 15 deg and it flies. I have done just over 70,000 k's in the last 3 years and have never had a problem since.

[Admiral coFF33]

sweet thanks GTtwin, *goes and gets new xmas tools from shed and gets to work*

[h3ff44]

sounds like you should reset your ecu and let the car run for a while and see if there are any pin out errors...

not sure if that would help but it sounds like the ecu is struggling at some point by resetting it the ecu learns everything again which might help u in this position..

[Jorrs]

maybe the auto gearbox is slipping under the boost pressure ?

[Jorrs]

if its a boost cut it will just kick in at a certain point and u wont be able to boost till u turn car on and of again, i experienced that on my 3sgte at 15 PSI, but when boost cut comes in it jsut stops boostin and slams the car.