#1: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Sun Jul 07, 2013 3:02 pm ---- so im not eager to fork out for new lambda unless i know its definately at fauly. was going to unplug (electrical plug) but leave the lambda in and run the car round for a day,see if it still has awkward idle as i've had no luck finding any possible exhaust leak
i know they have default values but of course you get the horror mongers online saying it can lead to massive overfuelling,melting pistons etc....
what would you guys say,safe or not?
#2: Re: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Sun Jul 07, 2013 3:04 pm ---- to clarify i AM talking about pre-cat lambda lol
#3: Re: Running without lambdas Author: V9977, Location: Athens, GreecePosted: Sun Jul 07, 2013 3:11 pm ---- You won't find-out much this way anyway..
What's the issue?
#4: Re: Running without lambdas Author: Steve206, Location: UKPosted: Sun Jul 07, 2013 4:10 pm ---- If its already faulty then it wont make a difference. Don't think they affect idle either.
#5: Re: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Tue Jul 09, 2013 11:36 am ---- well the issue is it seems to have a blow from manifold/block/cat area and due to that its sending the pre-cat lambda whacky (readings at idle jump between 0.1 & 0.8v,when it does this its obviously playing with the fuel/air mix and occasionally it drops revs then slowly finds idle again,ive hunted and hunted and cant find the leak,just want to make sure its only confused lambda thats causing it and not something else until i can find the dam leak. think it may have come from when had to hamme the s**t out of the old centrepipe/backbox to get it off so gonna try replace the mani to cat clamp seen as thats cheapest option to start with.
and i thought it was the opposite,lambdas only really used during idle or low revs,at throttle the ecu gauges it by throttle position/speed??
#6: Re: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Wed Jul 10, 2013 9:11 am ---- nevermind,tried it out this morning and did a BSI reset.....could smell the unburnt fuel within seconds from the drivers door lol back to leak-hunting i go,unless i get a good offer first (its up for swap/sale,im leaving the french side)
#7: Re: Running without lambdas Author: V9977, Location: Athens, GreecePosted: Wed Jul 10, 2013 9:28 am ---- λ-sensor reading is supposed to be fluctuating like that as it's a phase-locked loop, which 'floats' the value due to the way the element works.
#8: Re: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Wed Jul 10, 2013 11:16 am ---- yes but it shouldnt fluctuate THAT much should it? from what i managed to read up on them, 0.1v is lean,0.9 is rich,it should settle roughly,not bounce from extreme to extreme only time it settles is very low then goes to 0.8/0.9 then back down again. which is why i concluded air leak near lambda causing it to up the fuel mix to compensate when it isnt actually running lean......or am i miles off ya think?
#9: Re: Running without lambdas Author: V9977, Location: Athens, GreecePosted: Wed Jul 10, 2013 11:52 am ---- No it's a sinewave and peaks when you press on the accelerator pedal.
'Nearly impossible to look at the changing value of the loop and draw conclusions, appart from if it's stuck or something.
If there is a blow, fix it.
What's the problem?
#10: Re: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Wed Jul 10, 2013 11:57 am ---- as i said above dude,sporadically it loses idle,revs dip and climbs back. hasnt stalled at all. ICV,throttle body etc already been cleaned and checked. and its on proper plugs and a new bosch coil pack too. it only started happening since had to batter the old exhaust off the car. just wanna stop it until i can find/fix the leak and hopefully that will be it done. hoping its just the mani to cat clamp thats gave,and not the mani coming away from the head
#11: Re: Running without lambdas Author: V9977, Location: Athens, GreecePosted: Wed Jul 10, 2013 7:21 pm ---- So are you talking 'unstable idle'? Like when the revs pointer goes up and/or down from the steady state in a regular rhythm for brief periods, then it stops doing it altogether etc. How much drop (rpm) is it?
How many miles has it done since replacing the exhaust?
#12: Re: Running without lambdas Author: tommyhon23, Location: EssexPosted: Fri Jul 12, 2013 7:06 pm ---- Been driving mine for ages with one of my lambdas faulty. Seems ok but the occasional drop and idle of of revs seems to be getting worse, it even completely stalled while static the other day. Getting it fixed tuesday though:)
#13: Re: Running without lambdas Author: Mr-Tigger, Location: EssexPosted: Sun Jul 14, 2013 2:44 pm ---- let me know if new lambda fixes it,im pretty certain its the leak throwing it off tho as ive said,its blowing slightly still.
yeah it might idle fine all day,then sat at lights iddling normal (810ish) dip slightly,dip more to 400-500 then spring back to 1100 with a blip and back to 800ish again. might not do it for a week,might three times in a minute. seems to do it more when hot though. its easilly done 500-600 since exhaust was fitted and always done it. at first eml was on off,now its just on lol giving p0170 ((bank 1 running lean))
#14: Re: Running without lambdas Author: V9977, Location: Athens, GreecePosted: Mon Jul 15, 2013 12:33 am ----
Mr-Tigger wrote:
let me know if new lambda fixes it,im pretty certain its the leak throwing it off tho as ive said,its blowing slightly still.
yeah it might idle fine all day,then sat at lights iddling normal (810ish) dip slightly,dip more to 400-500 then spring back to 1100 with a blip and back to 800ish again. might not do it for a week,might three times in a minute. seems to do it more when hot though. its easilly done 500-600 since exhaust was fitted and always done it. at first eml was on off,now its just on lol giving p0170 ((bank 1 running lean))
I've had exactly this on the other car (2008, TU3A, 206).. Drove me nuts.
Sooo, reset the ECU 'auto-adaptation', stick some Super-unleaded in there and rag it... you'll be pleasently surprised.
#15: Re: Running without lambdas Author: kandlbarrett, Location: SwindonPosted: Mon Jul 15, 2013 9:06 am ---- Supporting and adding to above.
1) The lambda will fluctuate and should do so quite rapidy. The only garaunteed way to check lambda is with an osciliscope, Puegot Planet or other code reader.
2) You are wasting your time trying to diagnose lambda or anything else while you have an exhaust leak. Fix that first and fix it urgently noting that a pin-hole will affect lambda reading and, consequently, fueling.
3) a rich running engine can destroy lamdba sensors.
4) a rich running engine will quickly destroy your cat(s).
5) Most (not all) cars do not use lambda readings on idle or full throttle.
6) If fixing the exhaust and replacing lambdas (if needed) does not cure your problem it could be the MAPT sensor - if they are fitted to your engine. I would be surprised if it isn't fitted with one.
7) Also note that an air leak on the inlet can also cause strange symptoms.
8 ) Cleaning a stepper (ICV) is not a garaunteed fix and they do eventually need replacement.
9) With an exhaust leak and affect on fuelling the idle is probably outside the range that your ICV can control.
10) Fix your exhaust leak and fix it fast.
11) Fix your exhaust leak and fix it before doing any other testing.
12) Fix your exhaust leak before it costs you a lot of money.
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back to leak-hunting i go,unless i get a good offer first (its up for swap/sale,im leaving the french side)
