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wiered Idle problem

GIGOLO

By GIGOLO,
in General Maintenance

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GIGOLO Rising Star

GIGOLO

Posted
Posted

Hey everyone,

My car just started this weird idle problem where it hunts up to 1.5krpm then drops back to 1krpm and so on, normal driving is fine just when I stop at the lights etc. it idles really bad.

The car was driving fine Saturday night but when I started it Sunday, after the cold start came off it did this weird hunting thing.

When the AC kicks it the idle stabilises at around 1krpm, but when it goes off it starts hunting again.

I have tried:

-adjusting the idle screw

-tightening the BOV (GFB hybrid)

-checking all hoses to make sure they are connected.

I have a PFC, could some setting on this be the problem, although it has been working fine previously.

It has done this once before on a skid pan, but all I did was turn the car off and on and it fixed itself?

I am quickly approaching the zone of confusion.......................

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youngcodger Rookie

youngcodger

Posted
Posted

If you've got an R33 especially, it's your charcoal filter. This is a very common problem and you don't have to worry about it much. Depending on the conditions it'll have its goood days and bad days. If you really wwant to reposition your charcoal filter, you'll have to use up a fair bit of money.

superspit Mentor

superspit

Posted
Posted

make sure your dipstick is in properley, and inspect your oil filler cap seal!!! (just check them, it can't hurt!!) Mine (R33) stalls when I remove either one of the 2 when warmed up and idling.

INASNT Grand Master

INASNT

Posted
Posted
The charcoal filter is a filter for the air conditioning. It just simply filters the air so it is pure. However, it can end up slightly changing the idling of the car. It's nothing to worry about. I have the same problem on my R33, but it's severity varies.

Are you sure about this?

As i thought the charcoal filter is used to filter out petrol vapour from the fuel line. As some cars with the charcoal filter removed you can smell petrol vapout in the car when at the lights.

I also have a weird idle problem at the moment.

The car used to idle at around 1300rpm when i was coming slowing down to stop and then go down to 900 when the car was stopped. Now it idles 1300rpm all the time when warm and around 1700rpm when cold, which wastes a shiload of petrol.

I have a pfc and the idels are set at 950rpm and 1200rpm or so for cold start.

Where is the idel control screw in the engine bay and is this meant to over ride the pfc settings?

WazR32GTSt Grand Master

WazR32GTSt

Posted
Posted
where is the idel control valve located?

if its the same as an rb20 then its on the plenum near runner for cly #6 (called 'aac valve')

small square thing with a cylindrical thing attached. There should be a maroon plug going into it

remove the maroon plug

unscrew / tighten screw

replace maroon plug

idle changed!

just for the record (not sure if htis will help at all...):

i had htis issue where one day my car just started jumping idle from 500rpm to 2000rpm then stalled. Happened about 2 or 3 times on the same day.

When i got home, i got out the trusty old 'brake caliper cleaner' and cleaned the afm, took off the aac and gave it a clean, took off the O2 sensor and gave that a spray to remove any deposits on the probe, and reset the ECU

have never seen the weird idle problem again...

Cheers,

Waz.

  • 11 months later...
b1lly Contributor

b1lly

Posted
Posted

I think not .. as the guy below said, its for the vapour in the lines ..

which usually also reconnects to the intake so that the captured vapour can be sucked in by the engine again.

The charcoal filter is a filter for the air conditioning. It just simply filters the air so it is pure. However, it can end up slightly changing the idling of the car. It's nothing to worry about. I have the same problem on my R33, but it's severity varies.

Ant97GTR Grand Master

Ant97GTR

Posted
Posted

I had the same problem in my R33.....

One of the small vacuum hoses had come off the little valve thing right next to the screw to let air out of the cooling system, towards the front of the engine above the fuel rail. Popped it back on, attached a clamp and the problem never came back.

Hope this helps....

BH_SLO32 Proficient

BH_SLO32

Posted
Posted

Possible problems:

1. Air leak. Pinch the blow-by hose (the one connected to the intake plenum) and if the engine revs increase you probably have an air leak.

2. O2 sensor. At idle disconnect the O2 sensor and see if the hunting stops.

3. Plugs. Check condition.

Hope this helps.

Cheers

blackr32GTS Newbie

blackr32GTS

Posted
Posted

I have the same problem with my R32. I was stuffing around with air hoses on the weekend and now the revs bounce between 800 and 2000 when idling. Doubt it would be the charcoal canister as this only filters petrol vapours from the air. Guess I'll check air hoses around the plennum chamber.

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