Poss high idle problem/solution

[Chiffs]

Have taken the inlet manifold off today and tested the AAC valve and FICD valve.

Both working fine and giving the correct reading as per the manual.

Took the Air regulator off (page EF & EC 634 of manual)

Took it apart and there is a slide valve in it which is pulled shut by a spring and opened by a solinoid i guess.

Looks like the spring is a little old and is not capable of closing the valve.

Holding the valve shut

Holding it open

Question being would this cause a high idle. Easy fix being a new stronger spring.

Your thoughts, im thinking this may be the cause of a high idle?

 

[AJ4]

not necessarily unfortunately... the valve is attached to a bi-metallic strip, so the valve can be open at room temperature. Put it in the fridge and it'll close properly. It could still be out because of the weak spring, but the vavle may be designed to be opened that amount at that ambient temperature. Best thing to do is to take it off, and throw it in the bin, bloody nissan idle crap

 

[Chiffs]

so bit like a thermostat then, opens and closes depending on temp.

whats the electrical connection on it do then?

just supply power for it to work?

have tensioned the spring a bit so its now shut, inlet all back on now.
just got a few bits to reconnect and im going to try it out.

oh and how the hell did you know its got a bi-metallic strip in there, have searched the manaul and never saw anthing!

 

[AJ4]

I wrote this in another thread and can't be bothered writing again so I copied and pasted :lol:

4 : IAR Idle Air Regulator. Sits underneath plenum, works like an automatic choke ( but just for air ). Always switches on whenever you start the car and works on temperature, cold means open ( higher idle ) and gradually closes when intake heats up ( 3 minutes or so ? ). It has a heater inside so will always come on whether the engine is hot or cold and gradually close over the 3 minutes or so. Looks like a small cone with a disc stuck on the end with a pipe on each side.

The electrical supply is for the heater, but if you take the disc off you can see that its moved by a bi-metallic strip inside, so its possible for it to be in loads of positions depending on ambient temp. The important thing is that after the warm up period its completely closed, only something you can try by plugging it in and watching it I think.

In your case, it shouldn't work at all now as it should be open when cold and gradually close when hot, and you've adjusted it now so its already closed when cold Thats one way of curing the high idle I suppose

 

[campbellju]

I di dthe same the other week and at first I thought the same too but it is like Ross says. I added another turn or two on the spring just to make sure and left it at that.

 

[Chiffs]

So in thoery it should lower the idle then.

campbeelju did this improve your idle? Ive only tensioned it enough so the disc covers the hole, might still open and close, prob not though.

 

[AJ4]

take it off, throw it in the bin, and join the two pipes together ( for all the good the bloody thing does anyway ). Its 15 years old, the spring is knackered, the bi-metallic strip is knackered and the chances are the heater inside doesn't even work anymore :lol:

 

[Chiffs]

So best bet would prob be block hoses and bin it if it dont work:lol:

Easy to get to now as its only held on with one bolt and i have binned all the big brakets from behind the inlet manifold:lol: :lol:

 

[MarkTurbo]

I've got a problem with the idle on my R :sad:

When i start it up it idles at 1400 then as it warms up the idle slowly drops down and then sits at just under 1000 all the time :? That cant be right surely :der: :lol:

 

[Chiffs]

:fight1:

 

[mattygti-r]

I've got a problem with the idle on my R :sad:

When i start it up it idles at 1400 then as it warms up the idle slowly drops down and then sits at just under 1000 all the time :? That cant be right surely :der: :lol:

its that HKS FCD your running lol

 

[AJ4]

I've got a problem with the idle on my R :sad:

When i start it up it idles at 1400 then as it warms up the idle slowly drops down and then sits at just under 1000 all the time :? That cant be right surely :der: :lol:

Yep, you got a problem. Everyone knows that Pulsars idle around 1500 rpm, so I think you might have no leaks anywhere or some idle control components that actually work. I suggest you strip everything and hit it with a hammer and drill some small holes in all the pipes. Dont worry, we'll soon have you back up to normal idle speed

 

[hmmm]

I've got a problem with the idle on my R :sad:

When i start it up it idles at 1400 then as it warms up the idle slowly drops down and then sits at just under 1000 all the time :? That cant be right surely :der: :lol:

:lol:.

Looks like I have the same problem ;-).

 

[Olly]

I've got a problem with the idle on my R :sad:

When i start it up it idles at 1400 then as it warms up the idle slowly drops down and then sits at just under 1000 all the time :? That cant be right surely :der: :lol:

Hmmmmmmm one day it might not, for now your in the minority ;-)

 

[Chiffs]

Right its all back together, on start up idles at 1450rpm:-D then slowly drops to 1050rpm:-D

Soon as i rev it and let it go back to idle its reving at 1600-1700rpm:doh:

If i unplug the tps plug to set idle it sits at 1900rpm, idle screw is not fully in and has maybe dropped the idle to 1850rpm.

bloody thing, going to go and stick a match in the fuel tank tonight because this is really pissing me off:evil: :evil:

It seems to pull better though:roll:

Things i have done and changed are.

Air regulator spring tensioned abit to hold it shut
No fault codes
Maf re-earthed and reading 0.004 volts
AAC valve cleaned and checked correct as per manaul
New ecu water temp sensor
New lambda sensor
New plugs
Timing set to 20 deg
TPS set to 0.44volts or whatever it is in the manual
4 Black rubber bungs in place
No air leaks (i hope)
Throttle balance screws are at half a turn (not played with them as cant find anything about them):doh:

Smells bloody rich at idle, only way i can lower the idle is by reduceing the fueling using blue emanage (taking it away using the air flow map or by retarding the timing using the emanage). Still smell very rich though if not more so.

Mot time soon so HELP is needed please peeps

Thanks people

 

[AJ4]

Check the throttle butterflies are shutting properly.

Example, I went to look at another Pulsar last week that a friend was thinking of buying and the idle was all over the place and kept settling at different values after revving it. By pressing the butterflies closed it dropped right down to where it should be, so it looks like the throttle linkage / butterflies were sticking. Probably gummed up with 15 years of crap

Thats another thing to try anyway, adjust the butterfly adjust screw right in ( the one on the left hand side that sets the mechanical stop position of the butterflies ). I know it improbable, but after so many years the butterflies might have worn away on the edges a bit, allowing more air through, so the mechanical stop has to be lowered a little bit to compensate. Worth a shot...

 

[Chiffs]

Had a look at them when i had the inlet manifold off, gave them a clean too.

Noticed i could see a very small amount of light though them if held up towards the sun ( and i mean a very small amount)

When the butterflys are shut should they be airtight? or as near as damit?

Stops move easy so might just undo them so nothing is stopping the butterflys from closing anymore:roll:

 

[AJ4]

just be carefull, the stops are there to stop the butterflies jamming when they snap shut ( gear changes ). They should be all but closed though, as the idle air is taken through the four bypass slots.

 

[Chiffs]

I also measured the AAC valve voltage with the car running but the connector of and this was sat at 8.something volts.

Says in manual that it should bounce from 0-10volts to adjust the idle, could be a ecu problem i guess?

Injector resistance checked and ok, dropping resitor checked and ok.

Think i adjusted them so they where just touching the stops when the butterflys where shut.

Will double check them tommorrow.

Any other ideas.

 

[campbellju]

Have you tried to set the idle by disconnecting the TPS, blipping throttle to3Krpm a few times and then playing with the Idle air control valve? I've done everything you have and then found my valve needed to be shut completely to work properly! From the manual, this should only be played with when the TPS is disconnected or the car will accomodate the change. Mine has cams and idles at 1200 which I'm fairly pleased with, better than 1400rpm it used to be.