Which Of These Two Guides Is Correct

[WogsRus]

Hi so my problmes are. I tried to fix my idle, well there was no issues, car idled at 650 rpm, but when i tried to do the timing and set it as per manul, with the TP off the idle was at 1200 rpm. so i cranked the acc in as far as it would go and only managed to get it down to 900 rpm, and no more. I did the computer screw aswell and nothing, the idle woudl not increase or decrease any more then 650, i don't want it lower i just want to make sure it's ok.

So i followed the guide

http://www.skylinesaustralia.com/forums/in...=110431&hl=

And did the idle reset, and nothing, with the TP off and the ACC all the way in it would not go lower then 900 rpm, and that is all the way in. The manual from nissan states that the idle needs to be at 650 with the TP off.

Once i connected the TP the idle would drop down to 650 and that's it.

The other guide however says to disconnec the AAC valve, so whichone is it

http://www.skylinesaustralia.com/forums/in...=110434&hl=

The whole reason i wan tto do this, is to set my timing properly, and i can't set it at 650 rpm with the TP off as it does not allow me to do so.

HELP i'm going insane. I am going to clean the AAC today and cheack for vacume leaks to make sure it's all good.

I have heard that testing for vacume leaks is easy if you get some break cleaner with the small tube squirt extension and squirt arround all the pipes and manifold, if the rpm go up, then there is a leak.

Can somone give me a pointer as to how else do i check for leaks, exhaust and intake, i can't hear anything, but my fuel consumption is about 350 km in town for 50 liters and about 500kms on the higway.

BTW the car has a full 3" exhauts and cat and dump, FMIC, HKS POD, .8mm plugs, timming at 15deg at 900 rpm, boost at 8psi.

SO what is up??????

[WogsRus]

anybody???

[Risking]

On the throttle body there is a small allen head screw which adjusts the throttle plate position. It should not ever need adjusting and should have a coating of red or yellow paint on it. Has it been tampered with??

[WogsRus]

nah the TP has not been tampered with. I simply need to know which guide is correct. The one where you disconnect the AAC valve to set the idle or the one where you tunr off the TP to reste the idle?????

I rang nissan, but they are dickheads here in Tas, BLODY DJ, should be called DICK HEADS.

The TP is set as it should be 0.4V at idle

[RB30-POWER]

RB20 idle procedure uses the AAC disconnect.

RB25 idle procedure uses the TPS disconnect.

Hope that helps.

[WogsRus]

DAM, well for some reason i can not get the idle to go below 900 rpm with the TP off, going to clean the AAC valve and check for leaks tonight.

DAM IT.

[RB30-POWER]

If you can't get it to idle down, you either have a small vac leak on the plenum side or the air regulator is not closing when warm.

[WogsRus]

well last night i pulled the AAC valve out,a nd gave it a good clean. She was preaty dirty.

Put it all back in, tested the valves all close and open ect.

AND still no good, i had a look at the AAC valve and if all the valves are shit, there is always a small amoutn of air getting through.

So i puged it all back up, and nothing still can't get below 900 rpm as oper guide, so to check if there is a vac leak, i turned the AAC valve off and the car stalls. or dies in the ass.

I am goignt o use good old break cleaner to run arround all my piping to see what is goign on, but i don't think i have any leaks, will see.

ANY MORE ADVICE AS TO WHAT TO TRY?????????

[WogsRus]

""""""It could also be a vacuum leak.

If your idle screw is completely closed, there is definatly somewhere else that air is entering into the inlet manifold.

As was said above, my bet would be on the cold start idle control, or a vac leak, or for some reason a malfunctioning AAC assembly, where it is sitting open far too much when idling. Try disconnecting the power to the AAC assembly, that should close it and give you an idea of where the leak is comming from.

The car should stall if the AAC valve is faulty and opening too much, when you unplug it.

If that doesn't work, try pinching the bottom hose that runs past the AAC on its way to the cold start, if the idle drops when you pinch the hose = less air = stall, then thats your problem.

If that still doesn't work, check all your lines for tears or holes. Check all your gaskets on the inlet manifold, and check your throttle plate is properly closing."""""

From a Prevoius post. Ok so my cars stalls with the AAC valve disconnected, so what part is Faulty, i checked for operation and it definatly moves up and down with voltage ect. what parts do i need to replace to make this work??????

HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELP HELPHELP HELP HELP HELP HELP

Edited September 26, 2006 by WogsRus

[blind_elk]

If you disconnect the TPS, then the ECU doesn't hacve a "throttle closed" signal, and idles up to match the reading it is getting from the AFM.

If you leave the AAC valve connected, then the ECU is going to continually adjust the AAC to maintain idle stability.

So, it makes sense to disconnect the AAC valve before you make any adjustments to it.

[WogsRus]

That makes sence, but both the forum and the nissan mauls stated different. I am going to investigate tonight. AGAIN.

NissanSkyliner33_idle_part.pdf

[RB30-POWER]

If you disconnect the TPS, then the ECU doesn't hacve a "throttle closed" signal, and idles up to match the reading it is getting from the AFM.

If you leave the AAC valve connected, then the ECU is going to continually adjust the AAC to maintain idle stability.

So, it makes sense to disconnect the AAC valve before you make any adjustments to it.

Yeah on the RB20/26/30 the above is true.

However disconnecting the TPS (MAKE SURE YOU DISCONNECT THE THROTTLE SENSOR NOT THROTTLE SWITCH) on the RB25 fixes the AAC valve at a fixed duty cycle (not sure exact % Nissan don't state it) which is where the duty should be at required idle setting.

I've done numerous RB25 systems and never had trouble, weird...

Check to make sure you don't have a faulty power steer switch/sensor or neutral switch/sensor, make sure the AC and all loads are off or else the system may substitute a higher duty cycle on the AAC solonoid.

Forgot to mention make sure the timing is correct or else it will generate extra torque and it will rev higher.

Edited September 27, 2006 by RB30-POWER

[WogsRus]

and hence the problwm, how do i set the timing, if the rpm does not sit at 650 rpm with the TP off as per maunal to do timing???

I'm preaty sure i have solved it anyway, it's the cold start celenoid that is letting air through to rise the rpm.

[RB30-POWER]

yeah, if you remove the air regulator while its hot, it should be closed, if you look through the hole.

[WogsRus]

yeah well you can take it out cold and then put 12 v onto it and it closes.

I am sure it's this, as when you clam the hose off to it the rpm drops when hot.

[skidkid]

Edited November 17, 2006 by skidkid

[crack]

yeah, if you remove the air regulator while its hot, it should be closed, if you look through the hole.

my air reg is f**ked. closed all the time. does not start easily in the mornings. have to help it with a few prods of the accelerator. still idles fine though.

[RB30-POWER]

my air reg is f**ked. closed all the time. does not start easily in the mornings. have to help it with a few prods of the accelerator. still idles fine though.

If you undo the 4 screws holding it together, you can clean and lube the spring assembly in it and it will be good as new.

Just be careful of the gasket when you split the two halves once the screws are removed.

Once you have cleaned it and re-assembled, put it in the freezer for 5 mins and make sure you can see through the hole, just to check its working properly.