help with ls2 running lean please!

[v8kiwi]

hi guys, i have a 2005 hsv clubsport r8.

It runs the ls2 in it and have done long tube headers, full stainless exhaust, OTR intake, has a large cam, valve springs, lifters, pushrods etc, factory ecu and fuel system. About 580hp.

The car had been running fine for 4 months since it came back from the dyno the first time but then one day i noticed it to be running pretty shit, so i put the laptop back on it and noticed the the stft were getting up in the 30s and and ltft were getting up to 20. i added more fuel into it but had to put mass amounts in to drop the fuel trims and then next time i drove it the fuel trims were right back up. every time i add more fuel into it nothing happens and continues to run lean.

Since this issue has started i have and the injectors checked and cleaned, new fuel filter, checked fuel pressure (60psi), new o2 sensors, checked for vaccum leak, charge battery and check voltage from alternator and check all earths i can find.

When the car came back from the dyno the first time the injector duty cycle was 88% at full throttle and now its 99% and running very lean, but the fuel trims are highest at around 3000rpm+ which is where the cam starts to turn on.

I really need help as i have spent weeks tryna figure this out.

Any ideas guys? thanks, mitch.

[SultanHassanMasTuning]

did you upgrade your injectors?

also in diagnoses have your limited your max airflow vs rpm and ignition.

also check your MAF

[IDRIVEAG8GT]

If you're sure you've got plenty of rail pressure, that exhibits the classic symptoms of injectors failing. You running on E85?

[IDRIVEAG8GT]

Might wanna post a tune and log, and tell us what kind of injectors you're running.

[Mez]

Vacuum leak. You said you checked it, but keep looking.

Also, check for exhaust leaks ahead of the O2 sensor.

[v8kiwi]

the injectors are the stock standard ones but since having the issues they have been cleaned and tested at a injector shop and they are working fine. I dont think the injectors are too small because it ran 3 or 4 months fine then all of a sudden went bad and started going lean? and nope just pump gas 98. il try put up a log later on today. i will check for intake and exhaust leaks more and get back to you. thanks!

[v8kiwi]

here is the current tune

[v8kiwi]

after the first log was done i added fuel in or removed as required. so here is one and about 30mins later the second log was made

[v8kiwi]

so basically since the first tune of coming back from the dyno nothing im aware of has changed tune wise other than i keep putting fuel into, the numbers in the log above arent as high as they sometimes get too but it seems to be slightly incosistant.

[Xjas]

Looking at your logs it looks like a vacuum leak to me, your LTFTs are high but drop off as RPM and MAP rise.

[v8kiwi]

oh yea, that makes sense. i have looked for leaks but cant find any as of now? what is the best way to check for leaks? is there a certain way of doing it that is easier/better other than just physically checking?

[v8kiwi]

hi guys, ive spent all day trying to find a vacuum leak and have found nothing. i tried using smoke machine, taping up throttle body and putting compressed air in a vacuum hose, propane while running, engine start while running, carb cleaner while running and hooked up a vacuum gauge as well as factory map.

But what i did notice whilst looking over the logs was that bank two seems to be pretty good and the fuel trims only come on when bank one changes excecivly. could this mean anything? thanks

[Xjas]

I'm no expert, just pointing out what I saw in the logs but maybe it has a manifold gasket sucked in in the valley, that may explain one bank being more affected than the other.

[4evervette]

Vacuum leak. You said you checked it, but keep looking.

Also, check for exhaust leaks ahead of the O2 sensor.

What he said ,
Intake gaskets , even os2 sensors not being tight correctly

[ingsteve]

try to swap O2 sensor.

[MADWHIP]

Any luck Kiwi?