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

[Ben C34]

To properly check tdc you need a dead stop in the plug hole, or a dial indicator with a long plunger. Looking at it isn't good enough.

Does the PFC display what timing it is running? You should look at it , and if says 20 set cas to read 20 etc...

[rondofj]

It always says 15 on the commander (after warming up n idling), even when I set it to 20 yesterday (with TPS off), TPS connected it reads 15 at crank AND power fc as well.

[Dose Pipe Sutututu]

Omg did you not read anything?

Irrespective to what is set on the CAS the ECU won't show what's set. It will always think it's 15 even though the CAS has been dialled to 30

[rondofj]

To properly check tdc you need a dead stop in the plug hole, or a dial indicator with a long plunger. Looking at it isn't good enough.

Does the PFC display what timing it is running? You should look at it , and if says 20 set cas to read 20 etc...

^^ I do not know what is this. Dead stop/ dial indicator. haha

[XGTRX]

Sigh.

:mellow::mellow:

[Ben C34]

At some point you need to make a call and take it somewhere to get it sorted.

If all of this is going over your head just save the hassle and pay someone.

If you don't know what a dial indicator or dead stop (also called piston stop) is, Google it! Google how to check tdc. It's not hard.

Edited August 25, 2014 by Ben C34

[rondofj]

Why pay someone with no guarantee of a proper fix?? When its more rewarding and easy to ask, learn, try etc. And spend money buying my own tools/equipment rather than pay a workshop's labour. I would only go to a workshop after I have exhausted all avenues, tried everything and got as desparate as a cheap crack whore..

And I have already mentioned many times that the bov entry/power loss on shifts is a problem that doesn't really bother me anymore - I can live with it. Lets take this out of the equation, it will be my last fix.

Lets fix the timing first! hehe.. at least I discovered it was the timing that was causing power loss after all.

Edited August 25, 2014 by rondofj

[Ben C34]

Well so long as you are having fun with what you are doing that's all that matters.

Keep in mind by cranking in heaps of extra timing your risking popping your engine , which would cost more than getting someone to fix your current problem. I'm sure your tuner would freak out if you told him you added 6 degrees to the map and messed with the cas.

And by the way, didn't you cause the power loss by messing with the cas?

Edited August 25, 2014 by Ben C34

[Kinkstaah]

That last sentence makes me actually worried, just reading it on page 17 of this thread..

One does not simply add 6 degrees to the map and mess with the CAS

[XKLABA]

My guess would be Yavus set timing at 20deg with TPS connected and you have played with it at some point then reset it to what it should be, try setting it to 20deg with TPS connected and see how that goes

And I wouldn't be surprised if that puts the bolt on the CAS back in the middle

[XGTRX]

Because then you might muck around with something else, make it a bit lean and BANG... For this critical stuff you are paying a workshop for labour that includes knowledge, wisdom, and a system of doing things properly. One of your mistakes might cost you your engine, a good workshop won't make that mistake.

[rondofj]

Well so long as you are having fun with what you are doing that's all that matters.

Keep in mind by cranking in heaps of extra timing your risking popping your engine , which would cost more than getting someone to fix your current problem. I'm sure your tuner would freak out if you told him you added 6 degrees to the map and messed with the cas.

And by the way, didn't you cause the power loss by messing with the cas?

This is a strange one, I thought that as well, but it wasn't immediately too obvious on that day, maybe 2-3 days later, could have been my mind playing games.. I do think its the messing with cas, I keep saying before it was on the centre of the three bolts when i last set timing, and before I took it off to put Wolverines one in, now its almost fully clockwise at the same timing.

Could it be because I messed with the TPS before that and then brought it back to 0.41V @idle which is what it originally was. And thats all I messed with. And lost that white TPS plug cap.

Cranking extra timing on the pfc brought my power back to what it was before, maybe a bit sharper now, and it doesn't ping/knock at this level, does it mean its still unsafe? Dont understand this one. But crank up 1 more degree and it will knock at high rpm in 3rd.

Edited August 25, 2014 by rondofj

[rondofj]

My guess would be Yavus set timing at 20deg with TPS connected and you have played with it at some point then reset it to what it should be, try setting it to 20deg with TPS connected and see how that goes

And I wouldn't be surprised if that puts the bolt on the CAS back in the middle

^^ THIS seems like the most likely thing that has happened. Will be trying that. What do the others think?

[XKLABA]

FWIW 60 on the knock in a GTR is concidered high, mine never went past 20

[Ben C34]

Ask yavus?

[rondofj]

If he would remember. Mark tuned my car, will ring em up i think.

[Badgaz]

Stock ECU has ignition ramp to stabilise idle, thus when TPS is at 0.45v aka throttle off.. closed loop idle/o2 is enabled - this is why on a stock ECU when you're trying to set your base timing you'll notice it jumps all over the shop.

PowerFC I believe does not have ignition ramp to stabilise idle, so there's no need to unplug the TPS to set base idle and/or the base timing.

based on my logging I've found the idle control does.... I don't have 15 degrees set anywhere on my map yet log monitor shows 15 at idle.

[rondofj]

I still dont get how cranking up the maps 6+ degrees can be detrimental to my motor as it doesnt knock at that level and goes hard like before?

[XKLABA]

Wait till the motor burns a hole through a piston or through head to water gallery cause its preigniting cause its not tuned properly then you will see how detrimental it is

[GTSBoy]

Because you don't KNOW that it's not knocking. You are trusting very unreliable knock sensors to tell you that it's not knocking. It could well have more knock than is healthy and you can't hear it.

You have arbitrarily advanced the ignition 6 degrees everywhere and you DO NOT know for sure that it was actually retarded by that amount. It may well have NOT been retarded and in fact has some other problem causing your poor performance. The combination of the possible other problem + 6 degrees extra timing might not be real healthy.

Just because it now goes hard again doesn't mean that all is well with the world. It might, but it is not bulletproof by any means. And unless you can do a few of the basic verification checks that have been outlined you are flying very blind.

Edited August 25, 2014 by GTSBoy