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

[rondofj]

For the last time its NOT pinging.

[XGTRX]

For the last time its NOT pinging.

Sorry I thought it was but I re-read your posts and realised that it pinged at 30psi ha ha. Good one ha ha.

[Badgaz]

here it is:

These are probably the default powerfc settings....

[rondofj]

Ok I just went out n reduced all the acceleration pump settings in first column by 1.5 ms and increased decay time by 1, didnt make any difference to the bogging down on downshifts under load, sudden throttle input felt sharper I think, or maybe its my mind creating an illusion..

[Badgaz]

Decay time is duration and the first column is the amount to squirt. Duration shouldnt need changing. Can you video what it's doing?

[rondofj]

Sorry cant do mate, it wont help anyway, you have to be in car to feel it, and well the map tracer cells jump more than 5-6 cells down when it (bogging down losing power)happens, literally leaps downwards

Edited August 4, 2014 by rondofj

[Dose Pipe Sutututu]

If it's dropping that hard it could be a mixture of TPS and AFM issues.

You really need a data logit kit connected to it.

There are many variables you need to look at which you're unable to do via the PowerFC controller alone.

Best to bring it back to the tuner or like I recommended get your hands on a data logit kit and post up your logs

[rondofj]

haha..thats even harder - to find a datalogit kit for temp use. Only option is take it back to tuner..and get the same excuse that they couldnt find anything wrong/ didnt do anything to car.. you really think TPS could be an issue? - it does show varying voltage with varying pedal pressing, and is always within its usual voltage range..0.4- 4V or something, so thinking its alrite;

As far as I know, the only sensors that affect AF ratios are: CAS, AFM, TPS, O2 sensor, Coolant Temp sensor to ECU, MAP sensor - and probably in that order of importance. Probably in my case with PowerFC as some have said the O2 (switched off) and MAP sensor has almost bugger all effect.

Edited August 5, 2014 by rondofj

[rondofj]

More of this coming this weekend - a more thorough test with a good 25-30psi in - hoping to find some leaks. Stay tuned.. Sorry bloody images got oriented wrong..

Edited August 5, 2014 by rondofj

[rondofj]

here..

[Badgaz]

considering the jump in cells i'd say either tps or afm. CAS does not directly affect a/f ratios....its governs spark.

its cheap and easy enough to change tps...i'd start there.

another consideration is maf reversion.

[rondofj]

another consideration is maf reversion.

Yep - stock BOV is already blocked with a coke can plate to rule that out.. . Something else I must mention, the idle goes 200rpms higher with the headlights switched off and lower with it switched on - alternator maybe, the belts checked tight enough - not sure if this issue is even relevant but. And TPS voltage is actually 0.41V at idle - might need 0.45V judging by other threads.

All this hunting around for a solution- my problem could even be a bad ground. Something that has been on the back of my mind. Any common ground problem areas/ which areas should I look for?

Edited August 5, 2014 by rondofj

[XGTRX]

Have you checked your earths

[XKLABA]

It can still get reversion with the BOV blocked, when you shut the throttle the air built up by the turbo has to go somewhere and with no where else to go it goes backwards through the turbo to the AFM

That could also be causing and increasing the hesitation between gears

[Dose Pipe Sutututu]

fuarkkkkkkkkk

how have you wired your Z32?

Did you earth 1x cable to the chassis and 1x earth into the ECU?

If so.. there's one of your problem

both earths into the ECU (regardless whatever the interwebs says)

had the same issue with a S15.. each time the headlights were on.. the TP Load would increase as if there was more air going into the motor and AFRs dropped 1/2 a point... turns out with some hardcore googling.. DVS JEZ (legend) suggested to earth both together and into the ECU..

guess what? that solved the issue.

(yes I do tuning for fun).

[rondofj]

fuarkkkkkkkkk

how have you wired your Z32?

Did you earth 1x cable to the chassis and 1x earth into the ECU?

Nope both wires joined together and onto ECU as per SAU tutorial. I was actually thinking of wiring one to chasis but decided no go. By bad ground I mean check the earths from ECU, battery and other problem spots, clean metal, sand-papered joints etc. Think I'm goin to perfect my TPS adjustment to 0.45V instead of 0.41V, idle is 200-300rpms higher with O2 feedback off. Do u also have to disconnect the O2 plug, mine isnt?

[Dose Pipe Sutututu]

Disconnect your idle control valve disconnect your TPS disconnect your AAC then adjust the idle screw till its sitting flat bang at the idle prescribed by your PowerFC then plug everything back in

[rondofj]

Thanks mate, you fellas are real legends

[Trex]

Put up a new list of everything you have changed and checked. 6 pgs is a lot to read through.

Have you tried a recirc bov just for the hell of it? The symptoms you described. under load in a high gear, then changing to a lower one would make the power loss from over fuelling more pronounced.

[XGTRX]

It can still get reversion with the BOV blocked, when you shut the throttle the air built up by the turbo has to go somewhere and with no where else to go it goes backwards through the turbo to the AFM

That could also be causing and increasing the hesitation between gears

If you blocked off the bovs after the tune then this advice is spot on. So make a list of what have you changed after the tune would be a good start. I can't believe a tuner would let a car out like this.