www.gt4dc.co.uk
Maintain, Modify and DRIVE your GT-Four


It is currently Fri Mar 29, 2024 6:43 am




Post new topic Reply to topic  [ 77 posts ]  Go to page 1, 2, 3, 4, 5, 6  Next
Author Message
PostPosted: Tue Mar 14, 2006 12:37 pm 
Offline
Club Staff
User avatar

Joined: Wed Jul 13, 2005 12:14 am
Posts: 3265
Location: Camberley, Surrey
Car Model: ST205
Hi folks :)

Over the last few tanks of petrol I have noticed that I'm not getting quite as much per fill as I usually do. A tank of fuel used to get me somewhere between 300-320 miles per tank. Now I am struggling to get 270-280.

I suspect the oxygen sensor is on its way out, is there anyway to test this? Also is there anything else which could cause the poor economy?

The car is driving fine and I've noticed no difference in its performance.

Cheers :)

_________________
GT4DC Events Co-ordinator
1996 ST205 UK


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 12:47 pm 
Offline
Group N
User avatar

Joined: Wed Oct 05, 2005 10:38 pm
Posts: 175
Location: Petersfield
Car Model: None
Only other things are when were the plugs & leads last changed really as reduced sparking efficiency can cause poor consumption. No ideas for testing the O2 sensor though I'm afraid, and I think it only brings up an error code when it fails entirely :?

Cheers,
Mark

_________________
Mark - 94 Red Jap ST205 WRC - Gone but not forgotten :(
'06 Blue Merc E320 CDi v6
'89 Mica Blue MR2 Mk1b restoration project
"Don't make me come over there"


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 1:05 pm 
Offline
Junior WRC
User avatar

Joined: Tue Oct 04, 2005 12:44 am
Posts: 545
Location: Haywards Heath
Car Model: None
I have noticed the same thing in mine over the last couple of months.

My first thought was O2 sensor as well but I also wondered that it might be the weather at the moment.

I have a lot of early starts at work (IE driving at 0530) so the car does a large portion of its miles on a cold or semi-warm engine. This is gonna mean the ecu s chucking more fuel about which could also account for the change.

I did a trip to Stafford and back last weekend and got the mileage I would expect (330 miles from a tank of motoray driving) so this kinda confirms my thoughts. I'm going to wait until it's warmer before I decide if the sensor needs changing.


WOW! That was a long post to say very little :oops: But you may be having the same thing, Mike.

_________________
JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold :))
1982 Pontiac Trans Am 5.7L V8 (See my website)


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 1:23 pm 
Offline
Junior WRC
User avatar

Joined: Tue Oct 04, 2005 12:44 am
Posts: 545
Location: Haywards Heath
Car Model: None
I think I have found the procedure for checking the o2 sensor on page EG-137 of the ST205 service manual engine supplement.

But I am only half awake and can't understand what it is saying.

If you don't have the manual I can send it to you.

_________________
JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold :))
1982 Pontiac Trans Am 5.7L V8 (See my website)


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 1:30 pm 
Offline
Club Staff
User avatar

Joined: Wed Jul 13, 2005 12:14 am
Posts: 3265
Location: Camberley, Surrey
Car Model: ST205
Plugs and leads have been done fairly recently. Thanks for the reference Paul - I have the manual, off to read it now :)

_________________
GT4DC Events Co-ordinator
1996 ST205 UK


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 2:51 pm 
Offline
Group N
User avatar

Joined: Thu Oct 06, 2005 1:37 pm
Posts: 485
Location: Surrey
Car Model: None
:shock: :shock:

Hummmm mines really bad then, I stuggle to get 250 Miles per tank & on motorway trips its around 270.

I do alot of local trips from cold but I am sure its not going to knock off 80 miles per tank, so in a nut shell how do you test the O2 sensor then??

Where is the O2 sensor?? is it the one that connects to the multi plug by the alternator loom plug??

_________________
ST205 WRC #0002249


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 5:01 pm 
Offline
Group N
User avatar

Joined: Tue Oct 18, 2005 8:07 pm
Posts: 384
Car Model: None
lambda sensor is sticking out the top of your downpipe/cat section, right off the turbo exhaust.

cant miss it, bloody great thing held on by 2x12mm bolts

_________________
Sprint ST165 aka "The 500BHP Sledgehammer" #6 in the Toyota Sprint Series. GT3071 1.9bar


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 5:11 pm 
Offline
Club Staff
User avatar

Joined: Wed Jul 13, 2005 6:54 pm
Posts: 3484
Location: On Top
Car Model: None
Mike,
There is not really a sure fire way of checking teh o2 sensor without a Wideband, jam jar and some gas to create a constant oxygen content environment all contained in a bespoke container. You will then need to obtain the correct voltage output for the stock O2 sensor.

My O2 sensor is only 12 montsh old and I have also noticed my fuel consumption get worse in this real cold weather. I suspect the weather is more to do with it.

Another alternative is to plug in my wideband and see if your ecu is correcting to stoich at idle.

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 5:44 pm 
Offline
Club Staff
User avatar

Joined: Thu Jul 14, 2005 12:44 pm
Posts: 4067
Location: drinking devil fuel
Car Model: ST205
Another vote for the weather here

Even my Mundingo has dropped 60 miles per tank on the motorway in this cold

From what readings I see off the O2 sensor using my Apexi TT testing it in use is unlikely to produce any sesnible readings. It will however tell you if the sensor has failed completely (which my last 2 did) so might be of some use
You just need to hook a DVM into the O2 pin on the back of the ECU


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 8:05 pm 
Offline
Club Staff
User avatar

Joined: Wed Jul 13, 2005 12:06 am
Posts: 4743
Location: Perth, Western Australia
Car Model: ST205
Agree, cold weather + short runs = high fuel consumption

You could always buy Steves Unichip to take some fuel out :mrgreen:

_________________
Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 8:06 pm 
Offline
Junior WRC
User avatar

Joined: Tue Oct 04, 2005 12:44 am
Posts: 545
Location: Haywards Heath
Car Model: None
Does that mean I was right about something?

Wonders will never cease :D:D

_________________
JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold :))
1982 Pontiac Trans Am 5.7L V8 (See my website)


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 11:21 pm 
Offline
Group N

Joined: Tue Oct 04, 2005 6:53 pm
Posts: 211
Location: Castleford, West Yorks
Car Model: None
I thought that there was a test for the O2 sensor in the Chiltons using a muti meter?
I will have a look when I remember who I have lent it to.

_________________
Forever in search of knowledge (especially GT4 related)


Top
 Profile  
 
 Post subject:
PostPosted: Tue Mar 14, 2006 11:44 pm 
Offline
Club Staff
User avatar

Joined: Thu Jul 14, 2005 12:44 pm
Posts: 4067
Location: drinking devil fuel
Car Model: ST205
There are test methods but

The stock narrowband is such a poor effort it really should only tell you lean or rich (although it does appear to give a half arsed useful reading on boost in my setup)
The thing is a 10% drift in what it calls stoich would be very hard to detect but would effect cruising economy quite adversely

I think the tests in the manuals (RM, Chilterns et al) are more of a goosed test than a reading 100% right test


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 17, 2006 3:07 pm 
Offline
Club Staff
User avatar

Joined: Wed Jul 13, 2005 12:14 am
Posts: 3265
Location: Camberley, Surrey
Car Model: ST205
Well I managed to get about 295 from the last tank which is better, not totally convinced its the weather, I didn't notice any reduction in economy last winter. I'll keep my eye on it and wait and see. :)

_________________
GT4DC Events Co-ordinator
1996 ST205 UK


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 17, 2006 3:34 pm 
Offline
Junior WRC
User avatar

Joined: Tue Oct 04, 2005 12:44 am
Posts: 545
Location: Haywards Heath
Car Model: None
Neither did I last year mate but this year has been the coldest winter for 10 years so that might have been enough to tip the balance.

_________________
JDM ST205 (286bhp and 281lb/ft)
JDM ST202 (Finally sold :))
1982 Pontiac Trans Am 5.7L V8 (See my website)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 77 posts ]  Go to page 1, 2, 3, 4, 5, 6  Next


Who is online

Users browsing this forum: No registered users and 33 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group