Irratic idle
28 December 2002, 03:31 PM
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Hi, wonder if anyone could help me! I have a std. british `99`my impreza turbo. Its now covered 52000 miles but for the last 2500miles it has started suffering from an irratic idle. It doesnt appear to be missing or surging at any other revs! but is rather worrying as the problem appears to be getting steadily worse!
28 December 2002, 09:27 PM
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I have the same problem, however the subaru shop seems to think that it is the idle solenoid (a/c valve) and not the O2 sensor as I had previously thought. I am having it fixed on Monday and will post my thoughts on this thread after they repair the problem. I think that the O2 sensors are around 120 pounds.
30 December 2002, 06:54 PM
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I have the same spec car and have had the same problem for over a year. Sub garage plugged in machine and couldn't find anything wrong.
I have noticed that when I drive very easy for a while the problem goes away. However the first time I drive the **** off it again it comes back. Go Figure as the Yanks say!
Luckily I don't spend too much time in traffic.
Pat
I have noticed that when I drive very easy for a while the problem goes away. However the first time I drive the **** off it again it comes back. Go Figure as the Yanks say!
Luckily I don't spend too much time in traffic.
Pat
31 December 2002, 12:19 PM
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pat, that is exactly wot happens to mine!
sort of puts me off thrashin the **** off it! well, sometimes!!!
does nobody out there have any idea wot the problem could be???
sort of puts me off thrashin the **** off it! well, sometimes!!!
does nobody out there have any idea wot the problem could be???
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31 December 2002, 12:29 PM
#8
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From my experience (limited) it could be one of 3 things.
a) MAF Sensor
b) O2 Sensor
c) Throttle position sensor
Postman Pat
If your Subaru dealer can't identify the cause of the erratic idle, I would go to a different garage as they clearly ain't doing their job properly
. This is such a common fault on MY99's that any Subaru garage should pick this up immediately 
Cheers
Si
[Edited by SiPie - 12/31/2002 12:30:48 PM]
a) MAF Sensor
b) O2 Sensor
c) Throttle position sensor
Postman Pat
If your Subaru dealer can't identify the cause of the erratic idle, I would go to a different garage as they clearly ain't doing their job properly
. This is such a common fault on MY99's that any Subaru garage should pick this up immediately Cheers
Si
[Edited by SiPie - 12/31/2002 12:30:48 PM]
31 December 2002, 12:35 PM
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cheers Si, at least that narrows it down to only 3 relatively expensive pieces of kit!!!!
No, seriously, thanx 4 your input. Think its time i took it to local dealer, just hate payin their labour rates!!!!!!!
No, seriously, thanx 4 your input. Think its time i took it to local dealer, just hate payin their labour rates!!!!!!!
31 December 2002, 12:56 PM
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I'd have to go with the MAF sensor on this one.
I had an erractic idle, thought the MAF was ok, and that the idle sensor needed cleaning - which can be the case.
I popped in to Power Engineering and Merv very kindly plugged in the select monitor, no error codes, but he diagnosed the MAF was almost gone (which would have recked my engine ) due to it the ECU having to take fuel away to get the Lambda sensor working. In fact the SM also showed the car was running Co2 readings for WOT at idle Fitted a new MAF element, and straight away the idle returned to normal. The select monitor then showed the ECU having to add fuel to get the Lambda to kick in as it should.
Merv commented that erratic idle is usually (from what he has seen) down to the MAF, and at this stage its imperitive you replaced it ASAP. One piece of good news is you can now buy the element on its own without the housing (as your existing one is fine, its just the element). The element is about 80 quid + VAT against the MAF for 300+
The part number is 22794AA010 Meter CP-Air Flow.
The other thing to note, is that Merv said previously when a MAF has gone and replaced with the old OEM MY99 sensor, they would go again. This new one is contracted out to Bosch, and has only 4 pin-outs against the old ones 5 (but there is no diff in the job they do), and funnily enough he knows of no cases of the new sensors failing.........
Hope you get it sorted. Good Luck.
I had an erractic idle, thought the MAF was ok, and that the idle sensor needed cleaning - which can be the case.
I popped in to Power Engineering and Merv very kindly plugged in the select monitor, no error codes, but he diagnosed the MAF was almost gone (which would have recked my engine
) due to it the ECU having to take fuel away to get the Lambda sensor working. In fact the SM also showed the car was running Co2 readings for WOT at idle Fitted a new MAF element, and straight away the idle returned to normal. The select monitor then showed the ECU having to add fuel to get the Lambda to kick in as it should.Merv commented that erratic idle is usually (from what he has seen) down to the MAF, and at this stage its imperitive you replaced it ASAP. One piece of good news is you can now buy the element on its own without the housing (as your existing one is fine, its just the element). The element is about 80 quid + VAT against the MAF for 300+
The part number is 22794AA010 Meter CP-Air Flow.
The other thing to note, is that Merv said previously when a MAF has gone and replaced with the old OEM MY99 sensor, they would go again. This new one is contracted out to Bosch, and has only 4 pin-outs against the old ones 5 (but there is no diff in the job they do), and funnily enough he knows of no cases of the new sensors failing.........
Hope you get it sorted. Good Luck.
31 December 2002, 01:11 PM
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thanx scoobyjawa, u quoted a part number for the spare element, excuse my ignorance but who`s it for and have u any contact details?
are they aspecialist fit or can someone with 'some' experience fit the part?
are they aspecialist fit or can someone with 'some' experience fit the part?
31 December 2002, 01:13 PM
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Agree - MAF sensor. Which means absolutley do not drive the nuts off it. It isn't fuelling correctly (it will be lean).
This is where the select monitor isn't much good - the sensor might not be broken (yet), just not working correctly, so the select monitor is happy. To find that out that it's misreading, you either just wait for the engine to blow, or you need some proper software with someone who knows how the ECU works - so don't bother with (most) Subaru garages. Take it to someone who knows what they're doing. Personally, I'd just get the new (& very much tougher) MAF sensor, as you can't lose anything by doing this. If there's still a problem, then try something else, but MY99-00, just replace the MAF!
This is where the select monitor isn't much good - the sensor might not be broken (yet), just not working correctly, so the select monitor is happy. To find that out that it's misreading, you either just wait for the engine to blow, or you need some proper software with someone who knows how the ECU works - so don't bother with (most) Subaru garages. Take it to someone who knows what they're doing. Personally, I'd just get the new (& very much tougher) MAF sensor, as you can't lose anything by doing this. If there's still a problem, then try something else, but MY99-00, just replace the MAF!
31 December 2002, 01:19 PM
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thanx nom, will tootle around until i can fix the problem!
can u or anyone suggest where i source a new MAF or element as scoobyjawa suggested previously, and is it a DIY job or best left to a specialist?
can u or anyone suggest where i source a new MAF or element as scoobyjawa suggested previously, and is it a DIY job or best left to a specialist?
31 December 2002, 02:04 PM
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Hi andybrucefenton
Well the results were exactly what NOM had said...It was the MAF sensor.
"This is where the select monitor isn't much good - the sensor might not be broken (yet), just not working correctly, so the select monitor is happy."
The above quote from NOM's post is almost word for word that which the Subaru mechanic told me. The only difference is that for my car the fuel ratio was way too rich under power, which I had noticed for some time now. You will need someone to also rule out the possibility of the idle solenoid valve as this is what allows the air into the manifold during idle(well thats what I was led to believe). This does not mean that it cannot be the O2 sensor in the case of your car.
In my case the O2 sensor voltage was 0.83V or so at idle which was apparently correct.
My real concern is that I have only 46,000 Km on the car from new, and I also have a ITG filter on for the last 15,000Km. However I checked the intake last week and there was no gunk on the filtered side of the air filter or down stream towards the MAF sernsor.
Now I have no way of knowing what caused the failure although the technician seems to think that the sensors are just poorly made.
It cost me the exuivalent of 300 GB pounds to have it repaired and although I was over the 40,000 km warranty by 6,000km they still honoured the warranty in "good faith and customer satisfaction" which really impressed me.
I would like to know about the sewer stronger sensor and part number if possible NOM
The job is a diy. The filter box and hose to the engine should be removed as the sensor is in the hose part itself. One only needs to unplug the lead to the sensor and remove the two jibilee clips.
After that a phillips screw driver will remove the sensor quite easily. Please correct me someone if I am wrong, but this is what the tech guy told me.
Good luck and I hope this helps you
Well the results were exactly what NOM had said...It was the MAF sensor.
"This is where the select monitor isn't much good - the sensor might not be broken (yet), just not working correctly, so the select monitor is happy."
The above quote from NOM's post is almost word for word that which the Subaru mechanic told me. The only difference is that for my car the fuel ratio was way too rich under power, which I had noticed for some time now. You will need someone to also rule out the possibility of the idle solenoid valve as this is what allows the air into the manifold during idle(well thats what I was led to believe). This does not mean that it cannot be the O2 sensor in the case of your car.
In my case the O2 sensor voltage was 0.83V or so at idle which was apparently correct.
My real concern is that I have only 46,000 Km on the car from new, and I also have a ITG filter on for the last 15,000Km. However I checked the intake last week and there was no gunk on the filtered side of the air filter or down stream towards the MAF sernsor.
Now I have no way of knowing what caused the failure although the technician seems to think that the sensors are just poorly made.
It cost me the exuivalent of 300 GB pounds to have it repaired and although I was over the 40,000 km warranty by 6,000km they still honoured the warranty in "good faith and customer satisfaction" which really impressed me.
I would like to know about the sewer stronger sensor and part number if possible NOM
The job is a diy. The filter box and hose to the engine should be removed as the sensor is in the hose part itself. One only needs to unplug the lead to the sensor and remove the two jibilee clips.
After that a phillips screw driver will remove the sensor quite easily. Please correct me someone if I am wrong, but this is what the tech guy told me.
Good luck and I hope this helps you
31 December 2002, 02:14 PM
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As ScoobyJawa said...
- I imagine this is the right one! You can check by the number of connections - 4 & it's a new one (5 it's old).
I think in the States all scoobs were recalled to have this new part issued over the old one.
The part number is 22794AA010 Meter CP-Air Flow
I think in the States all scoobs were recalled to have this new part issued over the old one.
01 January 2003, 05:32 PM
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Postman Pat
The job is a diy. The filter box and hose to the engine should be removed as the sensor is in the hose part itself. One only needs to unplug the lead to the sensor and remove the two jubilee clips in order to remove the inlet hose.
After that a phillips screw driver will remove the sensor quite easily.
Hope this helps
HAPPY NEW YEAR TO ALL !!
The job is a diy. The filter box and hose to the engine should be removed as the sensor is in the hose part itself. One only needs to unplug the lead to the sensor and remove the two jubilee clips in order to remove the inlet hose.
After that a phillips screw driver will remove the sensor quite easily.
Hope this helps
HAPPY NEW YEAR TO ALL !!
02 January 2003, 12:35 PM
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Sorry guys - not been on for a while.
The part is available from any Subaru dealer (don't let them tell you they can't get it as they can) or from Power Engineering - they carry about 7 in stock, from what Merv told me - its that common a fault. Amazing with all this JD Power rubbish that Subaru never issued a recall for this one.
There are a lot of known cases of this sensor failing with completely standard cars too, so its hard to say mods have caused it.
As for the select monitor - its true that its not great for checking the sensor, but if you do real time logging on it via the graphs as Merv did, its easy to watch the Lambda and MAF readings and a decent mechanic should be able to diagnose a dodgy MAF from that.
Good luck!
The part is available from any Subaru dealer (don't let them tell you they can't get it as they can) or from Power Engineering - they carry about 7 in stock, from what Merv told me - its that common a fault. Amazing with all this JD Power rubbish that Subaru never issued a recall for this one.
There are a lot of known cases of this sensor failing with completely standard cars too, so its hard to say mods have caused it.
As for the select monitor - its true that its not great for checking the sensor, but if you do real time logging on it via the graphs as Merv did, its easy to watch the Lambda and MAF readings and a decent mechanic should be able to diagnose a dodgy MAF from that.
Good luck!
03 January 2003, 05:24 AM
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Hi all! (New to the list from sunny South Africa.)
I have the same (or similar) problem with my '96 GT. Only mods is a 76mm free-flow exhaust with dump-pipe, completely decatted. I can't say I've noticed the irratic idling to be worce when driving hard but it certainly is worce in the mornings with the first start or when ever the car is cold. Shall I also just start with the MAF and all as mentioned above or do you chaps know of some other problem relating to the older GT's like mine specifically?
Cheers
I have the same (or similar) problem with my '96 GT. Only mods is a 76mm free-flow exhaust with dump-pipe, completely decatted. I can't say I've noticed the irratic idling to be worce when driving hard but it certainly is worce in the mornings with the first start or when ever the car is cold. Shall I also just start with the MAF and all as mentioned above or do you chaps know of some other problem relating to the older GT's like mine specifically?
Cheers
03 January 2003, 01:15 PM
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Sinner,
Welcome to the board Well, in stark contrast I'm sitting here in wet old blighty, although the sun is out today, I'd almost forgotten what it looked like, not seen it since 1987 
Could be the MAF although the older cars have a more robust MAF than the MY99+ ones we're talking about, wouldn't rule it out though. Could also be a sticky idle solenoid. Best bet is to get it to a garage for a quick diagnosis session
Welcome to the board
Well, in stark contrast I'm sitting here in wet old blighty, although the sun is out today, I'd almost forgotten what it looked like, not seen it since 1987 Could be the MAF although the older cars have a more robust MAF than the MY99+ ones we're talking about, wouldn't rule it out though. Could also be a sticky idle solenoid. Best bet is to get it to a garage for a quick diagnosis session
15 January 2003, 09:04 PM
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ScoobyJawa and Lizzad
Fitted a new air flow meter yesterday. Car is working properly again for first time in 12 months (best £54 I ever spent). Pity the eejits in Belfast couldn't have diagnosed the problem. Last time I'll be donating cash there!
Lads thanks again for the gen
Pat
Fitted a new air flow meter yesterday. Car is working properly again for first time in 12 months (best £54 I ever spent). Pity the eejits in Belfast couldn't have diagnosed the problem. Last time I'll be donating cash there!
Lads thanks again for the gen
Pat
16 January 2003, 02:09 AM
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Postman Pat
I too am glad to see that you were able to fix the problem. It really does seem that these AFM are really rubbish. Did the technician tell you wether the car was running rich or lean under load i.e high power demand. Mine was running rich not lean as seems to be the case at times.
I too am glad to see that you were able to fix the problem. It really does seem that these AFM are really rubbish. Did the technician tell you wether the car was running rich or lean under load i.e high power demand. Mine was running rich not lean as seems to be the case at times.
16 January 2003, 11:03 AM
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mine was rich on idle and lean on WOT. Good thing is these replacement sensors seem more robust - I, nor Merv @ PE have not heard of any of the new ones failing. 
16 January 2003, 09:43 PM
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Lizzard
To answer your question he plugged in the diagnostic computer thingy which showed no faults so hey presto "nothings wrong mate!". Needless to say rich or lean was not even in the equation as far as he was concerned. I was just a pain in the rear customer with a good imagination for hard to find faults!
Anyway thanks to yourself and ScoobyJawa probs sorted. Cars running smoother and has more power too. Thanks again
Pat:
To answer your question he plugged in the diagnostic computer thingy which showed no faults so hey presto "nothings wrong mate!". Needless to say rich or lean was not even in the equation as far as he was concerned. I was just a pain in the rear customer with a good imagination for hard to find faults!
Anyway thanks to yourself and ScoobyJawa probs sorted. Cars running smoother and has more power too. Thanks again
Pat
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