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

[Ben C34]

That's good news.

Shit tune confirmed ...... flame suit on.

Unless it's the mysterious gates timing belt ignition scatter issue.

Edited August 3, 2014 by Ben C34

[rondofj]

Im hoping its a shit tune- despite taking my car to Unigroup 3 times, they just couldnt fix that bogging down prob, they went over but didnt touch the tune which they claimed is as good as it can be, their after-service is good.

I still have my pink label R34afm which I wana test though to see if the z32s farked. And maybe test the pcv valve cos boost went to the crankcase oil vapor vent area. And change O2 sensor.

[Dose Pipe Sutututu]

Don't plug your stock afm on, car will run like a bucket of ass as the scaling is different

[AngryRB]

what about a worn harmonic balancer/ key if it was moving or loose down there wouldn't that give some of the symptoms?

Edited August 3, 2014 by AngryRB

[rondofj]

Yeh I was meaning change the powerfc settings to r34 afm after putting that in. Harnonic balancer/keys fine, I inspected that/ did the timing belt myself.

You guys still dont reckon my O2s shot? Drives much better with it off. It must have been richening my car like a pig in the past.

Also dont understand how my dipstick was never blown off while driving all the time at 22psi but now with the boost leak test at 19-20psi it shot off like a rocket! Lol

[rondofj]

Also map sensor voltage BOST doesnt change but PRS does, not weird?

[Dose Pipe Sutututu]

Keep it disabled then

Even if you choose the right afm you'll be surprised it might not run properly. If the afm was again rescale your fuelling will be off

[wolverine]

The stock map sensor isn't referenced by the PFC as I said yesterday. Turn 02 feedback off. Like I said yesterday, your fuel economy usually won't change a great deal with a Unigroup tune. A new sensor is cheap enough and can be replaced at your leisure.

The PFC handcontroller item BOST (or whatever it is listed as) is for when you are using the Apexi boost controller IIRC.

[XGTRX]

What doesn't make sense is that you mentioned that you car was pinging...a rich environment won't cause it. There is something that isn't right with your ignition timing, I think. When it pings or idles crap is your engine noisey, like a belt shutter, noise, or something else. Sorry but what you are describing doesn't make sense.

[Badgaz]

A shame u don't live in nzwould have the datalogit plugged in and checked by now.... I'm beginning to suspect tune. Did they do your accelerator pump corrections if they were left stock it will go mega rich on gear changes.... Mine was going to the 9s before i tuned it out.

[rondofj]

Thanks mate, so I will leave the O2 feedback off till I get new O2 sensor (I know irts preferrable not to have O2 enabled but my car was tuned with it, so its best I leave it ON? Or not, and heres my accelerator pump enrichment that you asked about, do the adjustments look ok?

[Ben C34]

The O2 sensor should only be fine tuning the mixtures. It should be tuned woth it off to give the correct mixture, then turned on and checked after the tune is complete. It should barely make a difference on a properly tuned car whether off or on, especially immediately after being tuned.

Again, refer to your tuner. Ask him. He tuned it. We are guessing. It should be running 14.7 at cruise (pretty much) with or without the sensor. Which it doesn't seem to be due to your consumption.

[Badgaz]

i run my car with the o2 turned off permanently. those injector settings looks like stock settings. mine are attached but are for 850cc injectors....but they still make it fairly rich.

starting to sound like your tune didn't take everything into account. e.g wot & cruise only.

[Dose Pipe Sutututu]

turn off your O2 feedback, better yet just disconnect it.

Tuners always turn it off when they are tuning to disable the trims.

as for your acceleration enrichment, just set it low and work your way up till the car stop buckling.. sometimes it worth adding in more decay.

[Badgaz]

you have to adjust these like any fuel trims with a wide band. you can log and see the effect of enrichment when lift off and mashing the pedal, this is what a tuner would do if they are doing a complete tune.

[rondofj]

Default Accelerator Pump values for 33GTST - assume 34 is same or similar:

http://www.skylinesaustralia.com/forums/topic/103133-accelerator-pump-values/

[rondofj]

here it is:

[Dose Pipe Sutututu]

yeah different AFM different turbo = different values required

just write it all down, and start decreasing it for the RPM affected.. might actually reduce your buckling

[Ben C34]

Or tell tuner to actually tune your car as paid for.....

[XGTRX]

^^^^^ this

and why is it pinging

Edited August 4, 2014 by XGTRX