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


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Ron, have you actually matched the timing being displayed on the power fc in monitor mode to the timing you are setting yet? Like you are meant to. Or is 20 degrees just a random setting?

Nope I left it at 20 because it feels right (driving feel) here, and 'looks' right (CAS bolts) as when I last took it of. At 15 it feels like a huge power/torque loss, and no it doesn't ping at 20 at all (even though knock sensors arent reliable), after several hard pulls in 3rd then you will get the ocassional over 60 knock. So leaving it like this till I get a wideband.

Edited by rondofj

The power fc cant take a fuel content sensor and edit the tables on the fly. It also cannot accept a map sensor and allow VE tuning. I also thought that the timing number on the hand controller was the load table that the ecu is currently in, not the actual timing of the cams.

Map Sensor? it already does...you probably mean an IAT sensor for MAP based tunes....there are specific Powerfc's for this e.b Ljetro vs Djetro....more modern ECU platforms do both. Your last statement is horribly confusing. because ignition timing map with rpm on one axis and load (MAF or MAP loading calculation) on the y axis and the same for fuel map. Your hand controller will show you which cell you are in on the 20x20 map.

Edited by Badgaz

My last statement was trying to say that if you tuned the idle cell at 15 degrees on the ecu but the base timing was incorrect, the hand controller will show 15 degrees but the base timing at idle will be different.

Afaik there is no djetro for the rb25 r33.

oh ok. ldle control is not from the main map from what i've seen. The main map engages when throttle opens.....half the reason why you disconnect tps to set your base timing. think you are right for d-jetro....wonder if you could use a GTR pfc on an ECR33.

hmmm my idle goes quite loud and timing goes up 5 degrees when I disconnect TPS. Is this right? And how does one access the 'idle maps' with the hand commander?

You don't need to access the idle maps. Technically you don't need to disconnect the tps.

All you have to do is look at what timing the power fc is putting out and match the cas to that. Unplugging the tps just stops the timing fluctuating (ecu maintaining correct idle speed) to make it easier

. Surely the fancy hand controller that has been totally useless up untill now can do that? Isn't an option in the monitor section? Like I suggested a few times already

  • Like 1

My timing doesn't fluctuate much with TPS connected but it sure goes up 5 degrees with it disconnected, meaning 25 degrees in my case! Idle goes a lot louder and higher. 20 degrees is with TPS connected and yes Yavuz also said it doesn't matter if its connected or not when setting base timing, but in my case it sure does matter ;S. And yes as I said a few times earlier my 'monitor' mode in the commander shows idle always at 15 degrees when it settles / warm.

Edited by rondofj

So the cas is meant to match that....

And it doesn't matter it the plug is connected or not! Surely you get that by now. All that has to happen is the cas has to match the timing being displayed in the PFC.

The fact you mention it does matter in your case if the tps is connected or not goes to show you are still struggling with it.

Eg

Tps plugged in PFC says 15 degrees, set cas to 15

Tps unplugged PFC says 20, set cas to 20.

Nope not quite.

TPS connected >> timing on harmonic balancer = 20degrees. timing on PFC = 15 degrees

TPS disconnected >> timing on harmonic balancer = 25degrees. timing on PFC = 15 degrees

Which means CAS needs to be set to 15 degrees on harmonic balancer, but it don't go right like it used to at 15, and the CAS position doesnt look right at 15 to what I know it was before.

Edited by rondofj

do this..

go into powerFC set your timing to 20 degrees on N01,N02,N03 for the first 2 load points, i.e. P01, P02

then unplug your TPS, unplug your IAV and adjust your idle screw so the car idles at 800 rpm (or whatever the idle is on the powerFC)

make sure it is sittingi n the right load points, then match your base timing to 20 degrees.

thanks man, will do that :). That is the main timing map though not idle map, that ok? A properly warmed engine idle sits rock steady on N02, L02 >> 19 degrees on image a couple posts down

Edited by rondofj

One thing to check maybe your harmonic balancer has slightly twisted as it's old and worn and not showing you the true timing marks

Check by removing no 1 plug and put in a piece of wire or skinny screwdriver and slowly turn the crank by hand till that piston has completely reached the top and compare it to you crank pulley marks

If it is indeed out you need a new crank pulley or if not change it back to 15degrees

But the base timing does indeed affect the tune only with power fc or nistune not standalone ecus but

So if you say Unigroup did indeed tune you car with your cas in the position it is now at 20degrees and you retard it back to 15degrees

It will indeed drive like crap and the whole map will be retarded by 5degress

Usually they check the base timing before they start tuning you should fix the base timing back and get them to fix the tune

Better than just waiting for it to grenade and hoping for the best

these ones my bad

yep.. probably no need for N03, but just in case do it too.. because A/C usually touches that cell.

Also if you idle speed is too high it will show you slightly higher timing figure on the crank pulley

Did you make sure your idles speed was at 750rpm or what's is specified for that engine before you checked the base timing?

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