really bad fuel economy
13 April 2003, 10:14 PM
#1
Scooby Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2003
Location: Cheshire
Posts: 532
Likes: 0
Received 0 Likes
on
0 Posts
hi, even if i dont boot my MY97 turbo around and run under 2.5K revs, i still only get around 200 miles to the tank, and now ive just got it serviced my last tank lasted 175 miles???!!
would a ecu reset improve this? and how is this done. (i tried the jumpers and the throttle full and half but it didnt seem to do anything.
also its showing a throttle sensor error
oh yer, the only mod i have is a collins dump valve, everything else is completely stock
cheers
Sy
would a ecu reset improve this? and how is this done. (i tried the jumpers and the throttle full and half but it didnt seem to do anything.
also its showing a throttle sensor error
oh yer, the only mod i have is a collins dump valve, everything else is completely stock
cheers
Sy
13 April 2003, 10:36 PM
#2
Scooby Senior
Join Date: Oct 2001
Posts: 2,602
Likes: 0
Received 0 Likes
on
0 Posts
My guess would be a dodgy lambda sensor.
Throttle sensor may be off too I suppose
(wouldn't know about that) but the lambda could be misreading but still working (so the ECU wouldn't notice) - it would just give very bad economy
Throttle sensor may be off too I suppose
(wouldn't know about that) but the lambda could be misreading but still working (so the ECU wouldn't notice) - it would just give very bad economy
14 April 2003, 12:38 PM
#6
Scooby Senior
Join Date: Oct 2001
Posts: 2,602
Likes: 0
Received 0 Likes
on
0 Posts
You see if your fuel economy is cack; if it is, you're lambda sensor has probably gone
The lambda would be reading wrong but giving out correct looking readings, so an AFR meter would probably look OK (except under load when the lambda isn't used, at which point it would say 'ridiculously rich' even if it was working so may not get you very far...). But I suspect that once you'd sorted an AFR out, fitted it, etc. you'll have paid for almost as much as a new lambda sensor anyway
The lambda would be reading wrong but giving out correct looking readings, so an AFR meter would probably look OK (except under load when the lambda isn't used, at which point it would say 'ridiculously rich' even if it was working so may not get you very far...). But I suspect that once you'd sorted an AFR out, fitted it, etc. you'll have paid for almost as much as a new lambda sensor anyway
Trending Topics
15 April 2003, 11:20 AM
#10
Scooby Regular
Join Date: Mar 2003
Posts: 1,540
Likes: 0
Received 0 Likes
on
0 Posts
How far should a my97 Turbo be going on a tank or doing to the mile. Mine only does a little more than 200 to a tank but that is being driven hard. I am being to think now that this isn't normal ????
17 April 2003, 11:57 AM
#13
Scooby Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2003
Location: Cheshire
Posts: 532
Likes: 0
Received 0 Likes
on
0 Posts
right, just hammered through another tank, driving really hard everywhere and i get 200 miles to the tank? same miles as driving below 2.5K revs???
does this mean for sure its the lambda sensor as the lambda isnt used when driven hard?
Cheers
Sy
does this mean for sure its the lambda sensor as the lambda isnt used when driven hard?
Cheers
Sy
18 April 2003, 10:19 PM
#17
Scooby Regular
Join Date: Feb 2002
Location: oustide the asylum?
Posts: 3,306
Likes: 0
Received 0 Likes
on
0 Posts
The other possibility is the water temperature sensor is misreading. This gives similar symptoms to a lambda sensor failure.
Lambda sensor is more likely though, as they get plenty of abuse in a Scoob...
BTW I got 300 miles from the last 3 tanks in my MY96 UK - most of it motorway cruising. Usually, I get 250 miles from a tank locally - the car's never really warm.
Lambda sensor is more likely though, as they get plenty of abuse in a Scoob...
BTW I got 300 miles from the last 3 tanks in my MY96 UK - most of it motorway cruising. Usually, I get 250 miles from a tank locally - the car's never really warm.
19 April 2003, 02:06 AM
#18
Scooby Regular
Join Date: Apr 2003
Posts: 116
Likes: 0
Received 0 Likes
on
0 Posts
Hm.. I get about 250km from full tank to fuel light in my JDM 98 Forester, so about ... 12 mpg? Pretty nasty, until this thread I was buying all the reassurances like "oooooh turbos are always that way" and "well what do you expect for AWD in city driving". But I think its obvious now I'm looking at a sensor fault.
Is it far more likely to be the lambda sensors fault as opposed to.. the AFM? What other servicing can I do toward better fuel economy. Plugs?
Oh, where can I get a replacement lambda sensor? what kinda part number variations are there between the models, mines a JDM Forester S-tb
[Edited by Joth - 4/19/2003 2:10:03 AM]
Is it far more likely to be the lambda sensors fault as opposed to.. the AFM? What other servicing can I do toward better fuel economy. Plugs?
Oh, where can I get a replacement lambda sensor? what kinda part number variations are there between the models, mines a JDM Forester S-tb
[Edited by Joth - 4/19/2003 2:10:03 AM]
19 April 2003, 09:42 PM
#19
Scooby Regular
Join Date: May 2001
Posts: 449
Likes: 0
Received 0 Likes
on
0 Posts
I get about 220 miles average per fill up with my MY97
However, this is not a tank-full (60 litres / 13.2 gallons)
I fill up when on the 'E' (of empty), when the car takes about £36 of super -unleaded at around 79.9p per litre.
Works out around at 45 litres used (around 10 gallons) for 220 miles, giving around 22 mpg which is reasonable for mixed driving
So for a 'tank full' I would get a bit more.
What do you base your 200 miles on;
the tank capacity of 60 litres or just down to the 'E' on the fuel gauge?
Cheers
Rich
However, this is not a tank-full (60 litres / 13.2 gallons)
I fill up when on the 'E' (of empty), when the car takes about £36 of super -unleaded at around 79.9p per litre.
Works out around at 45 litres used (around 10 gallons) for 220 miles, giving around 22 mpg which is reasonable for mixed driving
So for a 'tank full' I would get a bit more.
What do you base your 200 miles on;
the tank capacity of 60 litres or just down to the 'E' on the fuel gauge?
Cheers
Rich
20 April 2003, 08:43 PM
#21
Scooby Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2003
Location: Cheshire
Posts: 532
Likes: 0
Received 0 Likes
on
0 Posts
i must run it down to almmost empty then!, it usually costs about £41 to fill up with optimax,
just filled up again, and the odometer was on 197 miles. (after mixed driving.)
ive tried phoning the sugested company (bob rawle developments) but no one ever answers (tried all week)
so can anyone help me with finding a replacement lambda sensor? is it wise to go to a breakers yard?
i dont really want to spend a fortune at subaru parts just to find that its not the sensor.
Sy
just filled up again, and the odometer was on 197 miles. (after mixed driving.)
ive tried phoning the sugested company (bob rawle developments) but no one ever answers (tried all week)
so can anyone help me with finding a replacement lambda sensor? is it wise to go to a breakers yard?
i dont really want to spend a fortune at subaru parts just to find that its not the sensor.
Sy
20 April 2003, 10:04 PM
#22
Scooby Regular
Join Date: Mar 2002
Location: Fcon Power Writer
Posts: 4,338
Likes: 0
Received 0 Likes
on
0 Posts
IMO your fuel consumption doesnt sound too bad...
Do a poll with every member of this BBS who owns a scoob of one sort or another, i bet that the 'average' milage on a full tank is between 150-180 miles.
If i listened to everyone on here i would be pulling my hair out.... I get an average of 120/140 miles per tank.. most of the scoob owners i know get an average of 200 miles with mixed driving.
What i would do is source a multimeter and check the voltage from the lambda sensor, This is how i determined that my sensor had packed up.
You can check the voltage quite easily at the ecu pin out.. at idle the voltage should fluctuate between roughly 200-850mv
Rob
Do a poll with every member of this BBS who owns a scoob of one sort or another, i bet that the 'average' milage on a full tank is between 150-180 miles.
If i listened to everyone on here i would be pulling my hair out.... I get an average of 120/140 miles per tank.. most of the scoob owners i know get an average of 200 miles with mixed driving.
What i would do is source a multimeter and check the voltage from the lambda sensor, This is how i determined that my sensor had packed up.
You can check the voltage quite easily at the ecu pin out.. at idle the voltage should fluctuate between roughly 200-850mv
Rob
21 April 2003, 10:44 AM
#23
Scooby Senior
Join Date: Oct 2001
Posts: 2,602
Likes: 0
Received 0 Likes
on
0 Posts
I get around 340 miles to a tank (50 litre fill) if I'm doing long journeys; never got below 240, & that was with 2-3 hours of 'tuning' session.
It's remarkable how many people have disfunctional lambda sensors but don't realise it, as most Subaru garages can't test for failure (well, complete failure they can, but not 'drift' which is the bad-fuel-economy bit). Think how many fail their MOTs on lambda failure - one time when it's accuracy really is tested!
I -think- (but not at all sure!) that the cost of a lambda is around £80. Which is 100 litres of fuel. And you're probably getting through around 15 litres more fuel per tank than you should be, so the lambda would be paid for in 7 tanks.
[oops - forgot to say - my car (UK MY00) doesn't actually 'use' a lambda sensor except for when it's being set up, and then it's on a wideband, which is probably largely why the economy is better than most on long journeys - but when I did use narrowband & closed loop, I still got around 290-300, which I believe is easily achievable]
[Edited by nom - 4/21/2003 10:47:35 AM]
It's remarkable how many people have disfunctional lambda sensors but don't realise it, as most Subaru garages can't test for failure (well, complete failure they can, but not 'drift' which is the bad-fuel-economy bit). Think how many fail their MOTs on lambda failure - one time when it's accuracy really is tested!
I -think- (but not at all sure!) that the cost of a lambda is around £80. Which is 100 litres of fuel. And you're probably getting through around 15 litres more fuel per tank than you should be, so the lambda would be paid for in 7 tanks.
[oops - forgot to say - my car (UK MY00) doesn't actually 'use' a lambda sensor except for when it's being set up, and then it's on a wideband, which is probably largely why the economy is better than most on long journeys - but when I did use narrowband & closed loop, I still got around 290-300, which I believe is easily achievable
][Edited by nom - 4/21/2003 10:47:35 AM]
21 April 2003, 10:48 AM
#24
Scooby Regular
Thread Starter
iTrader: (1)
Join Date: Mar 2003
Location: Cheshire
Posts: 532
Likes: 0
Received 0 Likes
on
0 Posts
tweenierob: funny that cos on a totally unmodified scooby turbo on parkers.co.uk is suposed to get 29.9 MPG, my one only has a dump valve, and that didnt make any difference what so ever to the fuel consumption.....
just been out in it and got it nice and hot. if i rev the engine out of gear, i can get the exhaust to pop???? its gotta be running rich right?? as its popping in an exhaust with 2 cats???
cheers
Sy
edited cos nom replied when i was typing this msg.
[Edited by SyHightower - 4/21/2003 10:52:35 AM]
just been out in it and got it nice and hot. if i rev the engine out of gear, i can get the exhaust to pop???? its gotta be running rich right?? as its popping in an exhaust with 2 cats???
cheers
Sy
edited cos nom replied when i was typing this msg.
[Edited by SyHightower - 4/21/2003 10:52:35 AM]
21 April 2003, 10:57 AM
#25
Scooby Regular
Join Date: Feb 2002
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
I run a MY00 Aust Spec, and I used to get 450 - 465km (277 - 287mi) out of about 50L. With the Link in a fairly rich tune (as mentioned by a great tuner, I might add) I am still getting 430km (265mi) out of 50L and that was with quite a few high acc and speed runs for datalogging purposes, I on average will do around 400 - 500km a week.
But then we also have a 3.9 final ratio in our cars...
Cheers
Brett
MY00 (Aust Spec)
But then we also have a 3.9 final ratio in our cars...
Cheers
Brett
MY00 (Aust Spec)
21 April 2003, 02:08 PM
#26
Scooby Regular
iTrader: (2)
Join Date: Oct 2002
Location: Chester
Posts: 1,052
Likes: 0
Received 0 Likes
on
0 Posts
Early wrx eg mine is a 93 only have a 50 litre tank uk has 60 litre tank i get about 200-240 miles for a tank.When you next fill up ignore the cost as petrol prices vary , look at how many litres you have put in and compare this to milage , you must do this from a full tank though.
Mark
Mark
22 April 2003, 05:30 PM
#30
Scooby Regular
Join Date: Dec 2002
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
In your first post you said that you have a TPS check engine light. I don't know your MY very well. I put a dump valve on MY2002 WRX and the clamp that holds the recirc hose on was in contact with the TPS conector and it caused the TPS to become unpluged. This would only happen if the dump valve is mounted on the intercooler next to the throttlebody.