car isnt idling properly

[CHILLI]

hey i have a gen 4 manual liberty sedan

I havent been driving the car much because I lost my license. But today I went for a small drive anyway just as a week to week thing to make sure things stay normal.

When I started the car for the first time in about a week it wouldn't idle properly and stalled unless I kept the revs up with the accelerator pedal. i had to use heel and toe and rev matching techniques to reverse out of my drive way . As soon as i started driving things were normal but when i got back the car was idling very low but it was holding idle and didn't stall . I noticed that if i gave the car a small rev ( 2-3 rpm) and didnt ease the revs back to idle it would stall .

I turned the car off and didnt drive the car for about 5 hours and then i tryed again and it did the same thing again .

im just curious as to what people think is causing this etc . i brought the car second hand and everything was normal but now that i havent been driving it often this has come up .

thanks Liam

[HyRax]

Are you only trying it once every week?

If so, then it could be as simple as the fuel in your tank being off. A tank loses about 2-3 octane in a week. If your tank is a few weeks old, then it could be really off right now. The ECU learns and adjusts things as it goes, so as far as your car is concerned, it probably thinks you have dodgy fuel in the tank now and it's having trouble doing things as simple as idling because the "last time" it was running, it had good fuel in it.

It ultimately won't break anything, and you'll spend your remaining fuel rather quickly without effort because it's not burning as efficiently as a fresh tank, but I suspect your problems will magically go away when you refill with fresh fuel.

[CHILLI]

hey HyRax

yes I'm only starting and driving the car once a week for a short period .

id say what you were talking about must be the problem i took the car for another drive today and it was behaving normally so that was a relief . the car has half a tank of fuel that is vortex 98 octane ( caltex premium ) this fuel is about 3 weeks old so it could be less then 90 octane by now.

do you think i should drain the remaining fuel out of the car and wait until I'll be using the car again then put fresh fuel in or just leave the fuel until i fill up next ? ( which could be more then a month away at the rate I've been using the car )

thanks for your advise though I really appreciate your time . cheers

[champ]

When I was working away, I also only started my car on the weelends. Same fuel, been in there more than a month, octane might 'be off' but no idling issues.

Is your battery holding charge & starting the car is ok? My older car had some idling problem, eventually battery died because the alternator was gone.

[Dropz]

Maybe try a bottle or 2 of that octane booster stuff from Repco or somewhere.

It could also be an injector problem, if it sits for a week at a time maybe the fuel is clogging up an injector, just run the car for a few hours with good fuel and it should iron out any fuel related issues, if not disconnect the battery for 24 hours to reset the ECU then try again with fresh fuel.

[HyRax]

hey HyRax
do you think i should drain the remaining fuel out of the car and wait until I'll be using the car again then put fresh fuel in or just leave the fuel until i fill up next ? ( which could be more then a month away at the rate I've been using the car )

No, leave the fuel - it's not going to hurt the car, it's just going to provide lousy burn efficiency, that's all. Normally I'd suggest refilling a bit now to reconstitute what's left in the tank a bit, but since you're not driving it much, just leave it for now and refill only 10 litres or so when it finally gets low.

Adding onto Dropz's second comment, when was your last service? You may want to bung in a bottle of Subaru Fuel Additive (to a full tank) just in case. This is normally done every service anyway, but even Subaru recommend adding it every 6,000K's. Will help to clean out the engine a bit.

[CHILLI]

thanks for your help everyone

[cooki_monsta]

hey HyRax
do you think i should drain the remaining fuel out of the car and wait until I'll be using the car again then put fresh fuel in or just leave the fuel until i fill up next ? ( which could be more then a month away at the rate I've been using the car )

No, leave the fuel - it's not going to hurt the car, it's just going to provide lousy burn efficiency, that's all. Normally I'd suggest refilling a bit now to reconstitute what's left in the tank a bit, but since you're not driving it much, just leave it for now and refill only 10 litres or so when it finally gets low.

Adding onto Dropz's second comment, when was your last service? You may want to bung in a bottle of Subaru Fuel Additive (to a full tank) just in case. This is normally done every service anyway, but even Subaru recommend adding it every 6,000K's. Will help to clean out the engine a bit.

What if I'm suffering the same issue but I'm driving it everyday?

I just posted in the 2.5i section. More details about my problem there.