South East Scoobies  

Go Back   South East Scoobies > The Garage > Engine Management

Engine Management For all your mapping,diagnostics and electronics

Reply
 
Thread Tools
  #1  
Old 29-01-2009, 09:30 PM
Scooby Wez Scooby Wez is offline
Silver Member
 
Join Date: Dec 2008
Location: Hastings
Posts: 635
Default Maf and lambda change

When i got my classic it had all the symptoms of the maf being on it's way out so changed it the problem with the hesitation stayed.After the 2 long run's i have done this got worse to the point this morning that on warm up it just did not want to go pulled over and let it get to temp and all seamed fine then the hesitation came back from approx 2.5k-3.2k making the car fell like someone was dabbing the brake on and off.So bit the bullet and got a new lambda and wow what a difference feels like a new car from the one i brought.All the hesitation has gone and now pulls like and train.Also the exhaust tone has changed i was not the only one to notice this which seams funny from just changing the lambda.The Subaru one was different on the probe end to the one that came out but both made by Bosch.Here's the one that came out
[img]http://img110.imageshack.us/img110/6404/lambdast22oy5.jpg[/img]
The Subaru one has a solid looking probe with a shield round it with holes in (Sorry forgot to take a pic)
Can the lambda failing make that much of a difference as i am even more shocked by how it goes now
__________________
Reply With Quote
  #2  
Old 29-01-2009, 09:40 PM
Scott.T's Avatar
Scott.T Scott.T is offline
Admin, Meets/Events Organiser.... formerly known as SilverSurfer
 
Join Date: Sep 2008
Location: Hastings, East Sussex
Posts: 9,483
Default Re: Maf and lambda change

Didn't I sat 'Lambda' when you mentioned it. Although I think you had already changed the MAF at the time.
The car will nearly always surge when cold until the lambda is up to temperature. The OE ECU is worse at this then the Apexi.

When they fail they tend to send a lean signal to the ECU hence the ECU will be thow fuel in and run rich at idle/cruise. This is why so many lambda faults are picked up at MOT as it will be running too rich to pass

The ECU can also use the offset it needed to apply to fuelling based on the lambda to adjust on boost fuelling, and hence on boost you may also of been running rich.

The later cars do this alot more then the early ones as the ECU is alot more inteligent. It can add a +/-14% difference. And can throw a CEL if it get this bad (a badly mapped car will also do the same).

The early cars tend not to throw a CEL and infact you can drve with the lambda disconnected. It runs smoother when cold like this due to the ECU not recieveing confusing signal from a Lamda going through the warming up process.
Reply With Quote
  #3  
Old 29-01-2009, 09:47 PM
Scooby Wez Scooby Wez is offline
Silver Member
 
Join Date: Dec 2008
Location: Hastings
Posts: 635
Default Re: Maf and lambda change

Yep mate you sure did The maf to be far did calm it down for a bit but with 1200 miles in ten days and a lot being at cruise motorway speeds think it killed it off.I want for a Subaru one as had seen a few reports of the pattern ones failing quickly so a bit more money but it's worked.
__________________
Reply With Quote
  #4  
Old 30-01-2009, 08:05 AM
majorscooby majorscooby is offline
Platinum Member
 
Join Date: Dec 2008
Location: gravesend, kent
Posts: 3,298
Default Re: Maf and lambda change

Quote:
Originally Posted by Scooby Wez
Yep mate you sure did The maf to be far did calm it down for a bit but with 1200 miles in ten days and a lot being at cruise motorway speeds think it killed it off.I want for a Subaru one as had seen a few reports of the pattern ones failing quickly so a bit more money but it's worked.
Just reading this thread and finding it an interesting read but just out of interest how much was that sensor from subaru? just curious.
__________________
Cooper man!!!!!
Reply With Quote
  #5  
Old 30-01-2009, 08:17 AM
Scooby Wez Scooby Wez is offline
Silver Member
 
Join Date: Dec 2008
Location: Hastings
Posts: 635
Default Re: Maf and lambda change

Now you need to be sitting down for this £163.89 and mine was one of the cheap ones they said When you think my new wheels with vg tyres cost £17 more it's a lot for a little sensor,but what a difference
__________________
Reply With Quote
  #6  
Old 30-01-2009, 02:53 PM
Scott.T's Avatar
Scott.T Scott.T is offline
Admin, Meets/Events Organiser.... formerly known as SilverSurfer
 
Join Date: Sep 2008
Location: Hastings, East Sussex
Posts: 9,483
Default Re: Maf and lambda change

The Subaru item is a Bosch sensor, but Subaru/IM have not released or allowed the OE item to be sold through the trade.

However, there is a Bosch equivelant for about £68. The only diffierence is I think you have to fit the OE connector to it.

I've run £30 universals without issue. I think these only fail on the models where the lambda is in the header due to the extra heat absorbed.

I currently run an OE WRX unit in the header and a wideband in the downpipe.
The OE in the header is even more expensive due to having a longer loom.
IIRC they are about £330...but got mine off Ebay (new-unused-unwanted) for about £20, and still in the Subaru/Graham Goode Racing box

http://www.grahamgoode.com/subaru/parts ... tem=GGS822
Reply With Quote
  #7  
Old 30-01-2009, 08:37 PM
doobydave doobydave is offline
Regular User
 
Join Date: Dec 2008
Location: The 'stings
Posts: 30
Default Re: Maf and lambda change

I've been meaning to get mine replaced to see if it removes the small but noticeable hesitation on my MY99 between 2-3 K rpm.

Are you saying (Scott) that I can just disconnect it and notice an immediate improvement if it is defective? (or get tone to )
Reply With Quote
  #8  
Old 30-01-2009, 08:46 PM
Scott.T's Avatar
Scott.T Scott.T is offline
Admin, Meets/Events Organiser.... formerly known as SilverSurfer
 
Join Date: Sep 2008
Location: Hastings, East Sussex
Posts: 9,483
Default Re: Maf and lambda change

Yep, just unplug the 3-pin connector
But only to do this to verify the fault (although they do all surge a little at light throttle 2-3K), expecially when cold/during the warm up period.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 



All times are GMT +1. The time now is 09:07 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.

Opinions expressed are not necessarily the opinions of SouthEastScoobies or any individuals directly or indirectly involved in this website. No responsibility is taken or assumed for any comments or statements made on this or any associated website. Visitors who use this website and rely on, or act on any information do so at their own judgement, discretion and or risk. SouthEastScoobies or its content providers shall not be liable for any loss or damage arising from or otherwise in connection with your use of SouthEastScoobies forums. It is not possible for the Administrators of these forums, or the Moderators participating, to fully and effectively monitor Messages that are submitted for infringement of third party rights. If you believe that any information within the forums infringes your legal rights, or gives cause for concern you should notify an Administrator or a Moderator immediately giving such information to enable the recipient to amend, delete or remove in its entirety the message, at their earliest convenience.