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

[rondofj]

I found what was causing my massive power loss as of recent. Timing. Checked base timing with light off no1 plug wire and tps disconnected- was 15, advanced it to 20 n took it for a drive no difference. Strange thing was with base timing at 15 my cas had to be almost all the way clockwise compared to before I took it off 3 weeks ago when it was in the middle @15degs.

Anyways I cranked up the temp timing adjust to 6degs+ throughout the maps and it went like a demon, like was usual for it, no knocks over 60 at 6-7degs+ adv timing and revving out 3rd. Tried 10 and 8 and knock went to 141 peak so back to 6 which seems its happy zone. And I know its only a temp adjust.

Question is why do I now have to crank up timing so much to get the crazy performance of 3-4weeks ago where there was no adjusting, just using base timing map values.

Is it because its dumping in a lot more fuel now and the extra timing compensates that to make a happy medium of operation and power? If so wheres all this extra fuel coming from?

Edited August 24, 2014 by rondofj

[Ben C34]

Tell your tuner you added 6 degrees to your map and see what he says.

Maybe seeing as you have taken off your cas due to the reverberation issue initially making you hunt random problems you somehow made a mistake timing the engine correctly.

[Ben C34]

And what extra fuel? You don't have a wideband so stop guessing.

[Badgaz]

Base timing is critical when setting a tune(or in general really), if you're CAS has physically changed position that could tell you something.

[Ben C34]

And being retarded as you found it will increase fuel consumption.

Disconnecting the tps is the correct way for the stock ecu. Is it the correct way for a power fc?

[Badgaz]

Yes, idle control can effect final timing on pfc. Disconnect tps and set your base timing to match what the powerfc shows on the monitor.

Edited August 24, 2014 by Badgaz

[XKLABA]

And do so off the coil not the wire controlling the coil, that is off

I open the slide on the timing light and hold it against the front of the coil

[rondofj]

You got a point- I connect a spark plug lead wire between no.1 spark plug n coilpack and the slide on the timing light is off this lead. This wrong? TPS plugs brown n black are disconnected at this point. Disconnecting TPS makes idle louder n not too happy.

And the timing is currently set to the 5th white mark (20deg), 1st red mark is zero right? This made no noticeable diff to when it was 15degs which I know is what it should be. BUT advancing the map 6-7 degs was like night n day! Like going from 230-300kw. All that torque/pull.

Powerfc map once warm still shows idle at 15degs not 20, with the 6deg advance it shows 21degs of course.

The really strange thing I found after replacing cas with Wolverines one then mine- I had to have it rotated almost fully clockwise to achieve the 15degs on the crank marker. Whereas before when I set the timing after doing belt, the cas was in the middle (bolts in the middle of the slide holes) @ 15degrees. Does the cas move the whole ign map like the ign advance does?

Which means I need to advance the cas 6 more degrees so I wont need to add the +6degs of temp ign adv to powerfc settings each time I drive? This sound ok? I found that connecting the TPS back moves the timing 5-6 degs back, so my 20degs base timing is actually 15 since it was set with TPS disconnected. Also the TPS is 0.41V at idle not 0.45.

Edited August 24, 2014 by rondofj

[GTSBoy]

You got a point- I connect a spark plug lead wire between no.1 spark plug n coilpack and the slide on the timing light is off this lead. This wrong? TPS plugs brown n black are disconnected at this point. Disconnecting TPS makes idle louder n not too happy.

And the timing is currently set to the 5th white mark (20deg), 1st red mark is zero right? This made no noticeable diff to when it was 15degs which I know is what it should be. BUT advancing the map 6-7 degs was like night n day! Like going from 230-300kw. All that torque/pull.

Powerfc map once warm still shows idle at 15degs not 20, with the 6deg advance it shows 21degs of course.

The really strange thing I found after replacing cas with Wolverines one then mine- I had to have it rotated almost fully clockwise to achieve the 15degs on the crank marker. Whereas before when I set the timing after doing belt, the cas was in the middle (bolts in the middle of the slide holes) @ 15degrees. Does the cas move the whole ign map like the ign advance does?

Which means I need to advance the cas 6 more degrees so I wont need to add the +6degs of temp ign adv to powerfc settings each time I drive? This sound ok? I found that connecting the TPS back moves the timing 5-6 degs back, so my 20degs base timing is actually 15 since it was set with TPS disconnected. Also the TPS is 0.41V at idle not 0.45.

Points listed more or less in the same order as yours above.

Using a plug lead is correct. The wire they are telling you (everyone) not to use is the loop wire on the igniter.

The ECU can and will NEVER know that you have moved the CAS. The CAS is THE signal that the ECU uses to tell it what the angle of the motor is. The ECU only ever knows what the angle of the CAS is. You could set it to -40° or +60° and the ECU will still think it's 15°, because that is where the ECU ASSUMES the CAS will be set to.

Yes, moving the CAS affects the whole timing map. It has to. There is no difference between twisting the CAS and adding a blanket amount in the ECU.

If you have a difference before and after doing a timing belt or otherwise removing and refitting a CAS, then it shows that it has gone back together wrongly.

When idle is registered (TPS at idle position) then the ECU will command idle timing, which may only be 10° or similar even with base timing set to 15°.

[XKLABA]

Yeah lead is a correct way of doing it, I only mentioned it cause you said wire which is not the right way

Cas also times the injectors so don't play with it to much

I've never understood the disconnect TPS thing, must be a RB25 thing I don't do it to either of my 26s

[Dose Pipe Sutututu]

Yeah lead is a correct way of doing it, I only mentioned it cause you said wire which is not the right way

Cas also times the injectors so don't play with it to much

I've never understood the disconnect TPS thing, must be a RB25 thing I don't do it to either of my 26s

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.

[XKLABA]

Uh huh, and is that a 25 thing cause I have never done it with a 26 even with stock ECU

So Ron should be setting base timing with the TPS connected then

[rondofj]

Yep TPS connected it reads 15 degs, TPS unconnected it reads 20 degs and idle is louder / unhappy.

Set temp ign this morning to 7degs+ and it went like a cut snake. 3rd gear it hauls...pretty HARD. No knock levels to worry about.

So do I advance my CAS to 7 more degrees even though it wont read 15 degrees base timing??, then I wont have to do a temp ign adjust on the powerfc everytime. Because right now at 20degs (TPS disconnected) and 15degs (TPS connected) the CAS sits almost fully clockwise, before it was in the middle (with bolts in the middle of the sliders @15 degrees base timing).

Grey TPS plug CAP is missing (lost it) this plug one is for auto transmission cars - this cap doesnt join the connectors on plug right? So I wont worry bout it.

Edited August 25, 2014 by rondofj

[GTSBoy]

At this point, if I were you, I would pull #1 plug out and check TDC on the crank pulley. And whilst there I would check the cam alignment marks. Throwing random CAS adjustments at a sick car is not guaranteed to end well.

[rondofj]

At this point, if I were you, I would pull #1 plug out and check TDC on the crank pulley. And whilst there I would check the cam alignment marks. Throwing random CAS adjustments at a sick car is not guaranteed to end well.

Does this mean turn the engine by hand (socket to crank pulley) till you see piston crown on no.1 plug hole? Then check cam alignment mark on crank bolt and cam marks on top?

[Dose Pipe Sutututu]

^ yes

Use a thin long rod and place it straight down, rotate the motor clock wise by hand till Cyl 1 is TDC and check marking on the crank.

I wouldn't randomly blanket timing onto the motor, it's asking for some smashed ringlands

[rondofj]

So even if it doesnt knock over 60 (blanket timing), it is still dangerous? Cos I it doesnt knock hard/at all below 7 degrees advance.

Still gotta remove fan and radiator to put a socket down the crank bolt yeah? That fan is a real bitch to remove, my hands arent small lol.. And not to forget the rad bottom hose.

[Dose Pipe Sutututu]

remove the bottom splash guard, jack up the car, crank it bottom up

[rondofj]

ahh that was clever mate, thanks ^^

[Ben C34]

Keep in mind the factory knock sensors are shit, and old. I certainly wouldn't trust it. You have your doubts about the afm and cas being old and dodgy, so why are you happy to trust the knock sensor?

So going back to the start of all this it seems you caused the timing issue because of taking off the cas. The car will still have the initial bogging on shifts due to the very likely reverberation and bov return issue.

You still need to get that fixed. You have done so much worrying, time wasting and random stuff it's crazy. Yavus agreed it was jumping around the map, the only way it can do that is reverberation. The afm can't be dodgy like that and the cas also be can't cause that (It has nothing to with loaf)

Also, something to consider, if the afm was dodgy your car was tuned for it! Meaning if you replace it with one that functions differently your car will not be tuned correctly and will run shit....

Fix your bov return.