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Power Loss On Downshifts, Bouncing Idle And Slight Hesitation At Specific Rev Point -R34Gtt


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Your right, NEO one starts opening at 82C right, I cant adjust the 'temp' in the water temp correction, just the correction values - it has 1.00 and 1.00 at 80C and 1.04 and 1.07 at 50C, maybe bring this down to 1.00 and 1.00?? (low and high load correction that is)

maybe you should borrow someones splitfires cause those OEM ones you got sound like they could be duds.. hard to believe these issues don't show up on a dyno, if it pings in 3rd then

that's a tuning issue isn't it?

Rarely pings on third, or second. I've turned off the airflow warning in power fc function settings under etc, will test tonite to see if it still throws check engine light.

if it pings in any gear then there's an issue.. even lugging the shit out of 5th gear shouldn't ping...

you really need to borrow/invest in a FC Datalogit kit and do proper logs, that will helps all of us understand the issue

Update- found out whats causing the check engine light in high boost/redline, mostly on 2nd- the airflow voltage going past 4.8V. Turn the airflow warning off in power fc ETC FYUNCTION SELECT and no check engine light. Tonite I reached 4.88V and 4.915V on 2 power pulls in 2nd and 3rd- no check light. Most times the light comes on the peak voltage is around early 4.8ish V. But that doesnt solve my other problems, not much idle bounce been happening but the other probs are there. And temp is slow to reach max 78C, change thermostat to R34 82C one? Or adjust water temp correction at 60C

there is no need to mess with the water temp correction. when you do a map trace which load rows are you reaching? i'm wondering if your calibration for your AFM has been messed with....have you tried running with another z32 afm?

Tried different afm but not enough space to test- didnt get idle bounce/ slight hesitation @1800rpm but got bit of the bogging down at downshifts. Im wantin to change thermostat/adjust water temp corr cos it takes long to reach 78C and runs rough beforehand (enrichment)

idle hunting is usually because mixtures are too lean or your AAC valve is rooted and needs some love.... have you cleaned your afm and resoldered any dry joints?

Yeah as mentioned earlier in OP, done all that. But why does my afm throw check engine light at 4.8V+??? It should be 5V+ according to Paulr33 in another post

Edited by rondofj

Tried new CAS now thanks to Wolverine in here, no change to problems - CAS ruled out now (and yes timing was set to 15 degrees with timing gun).

Found something else- got the annoying idle hunting and 'sticky stutter/jerk at 1500-2000rpms in long traffic drive- switched off O2 feedback in PowerFC and it went away. Was much smoother too. But then after my drive while idling it was a bit rough (no hunting) and switching O2 feedback on smoothened it so confusing. Yavuz did mention O2 sensor is on the way out soon but not to worry yet. Typ voltage 0.5-1V.

Disconnecting MAP sensor makes drive a bit rough and values for PRS and BOST on powerfc sensor check become 0.00V. Connecting it gets PRS to 2.7ishV at idle and BOST is always 0.02V-doesnt change even while driving but PRS does change 2.7-2.8ish V. Is my MAP sensor shagged?

All this doesnt solve the bogging down and losing 70%power for 5secs during downshifts esp under load.

Next move is drive in low rpms with Z32 disconnected and boost leak test with compressor.

Edited by rondofj

All of this diagnostics is so pointless untill you check for boost leaks.

Once they are ruled out then the only explanation for the shit running and economy (if it continues to be that way) is a poor tune.

I would have thought a quick trip to a tuner should be able to sort out all your issues. He should be able to look at all the values and see what's off, and also look at your tune itself. Sounds like it's dumping fuel on low loads, is there black smoke coming out when it is loss of power? Not sure if all that has been covered above. Just thought I would throw in my 2 cents.

Apparently the tuner is an absolute guru so no one is questioning the tune.

Just putting heaps of time into other areas.

  • Like 1

Yep tuner is God and tune cant be questioned. Blame the tune n u get flamed! At least here you do.. Drove with O2 feedback off and it drove a lot better, more torque, smoother, no jerking n bouncing idle. Apparently my O2 sensors stuffed, its one of those PES items from South Aus, put in only 3 yrs ago.

Well heres progress. Aint tested it yet... post-49401-14070458601323_thumb.jpg

Edited by rondofj

You will be surprised, found just one- a little hose to plenum that used to go to purge valve at firewall, that hose had been blocked off with a bolt through the end and zip tied -theres a leak thru that bolt as determined by soapy water on 'boost'. Try as I might, didnt find any more- none of the intercooler joiners nada, was gettin dark, didnt spend too much time

Edited by rondofj

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