Lambda exhaust sensors

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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Lambda exhaust sensors

Post by colb »

Have had a couple of codes set on my 1999 1.8 Z3
Pending Code P0340 Camshaft Sensor A circuit Malfunction Bank 1 or Single Sensor
I have put in a OEM BMW replacement and so far no codes have returned for this.

The second code it set was P0170 Fuel Trim Malfunction Bank 1, it also brought on the Engine Check Light.
I reset the code and since changing the Camshaft Sensor it has not come back.

Having upgraded my Engine Check Software I can now look at the Lambda sensors and have noticed the following readings

Lambda Bank 1 Sensor before Cat voltage reads Min 0.07 Max 0.875 Avg 0.4718 at idling.
It produces a steady wave form on the screen. Wave form also at revs.

Lambda Bank 2 after Cat voltage reads Min 0.48 Max 0.4905 Avg 0.4879 at idling
The wave form is a flat line
At 2000 RPM the eadings are Min 0.33 Max 0.351 Avg 0.3576
at this rpm the line falls on my screen then returns to the flat line reading when back at idle.

What should I be seeing the flat line or a wave form the same as the first sensor?

Car runs ok nice steady tick over and smooth drive, exhaust tail pipe is black but I am told they are all like mine.

Would appreciate an interpretation as to what I am seeing with the Lambda sensors if anyone can oblige before I start changing them.

Thanks
Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
mikez3oldgit
Joined: Sun 23 May, 2010 00:33
Posts: 39

  Z3 roadster 1.9

Re: Lambda exhaust sensors

Post by mikez3oldgit »

Hi, the 1999 facelift 1.8 z3 has both pre end post cat lambda sensors.
Good luck with chasing out any gremlins.
Regards, Mike.
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Lambda exhaust sensors

Post by Robert T »

Regardless of the meaningless Model Year, the facelift was 04/1999, so any cars built after that are facelifts.

Also the UK facelift 1.9 is an 8v 1896cc M43 engine, but is badged as a 1.8. There was also an 1800cc variant, but it was not available in the UK.

R.

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Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Tez
Joined: Tue 03 Jul, 2012 09:55
Posts: 84

  blank

Re: Lambda exhaust sensors

Post by Tez »

Hi Guys

Just to confirm something here, i have a UK facelift 1.9 8v 1896cc M43 engine and mine was built in May 1999, regestered in Aug 1999 so the facelift was available late 1999 and not after 2000, mine also has just one sensor before the cat only.

This year model has caused me so many problems since i have had it due to the crossover, even the exhaust systems totally a pain in the arse to get being a slot push on system, i had weeks searching for a new one and no one could help, tried all the usuals, kwik fit, formular 1 etc etc all told me cant do, in the end i went custom built stainless steel ! :)
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Lambda exhaust sensors

Post by colb »

Wow some different opnions on the model of my Z3 and what it should have.
The options sheet for my car show it was 01 December 1999 production and is a Z3 (Eur) E36 (7) with a M43/TU engine
It is badged as a 1.8 although the options sheet shows 1.90 as the displacement.
It was first registered in the UK 1st March 2000.

I will check underneath to see how many sensors I have fitted, I suspect it is 2? other wise what is my software looking at when it shows Oxy sens 1 and oxy sensor 2 when on live data?



Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
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Deano1712
Z Register organiser
Joined: Sat 05 Aug, 2006 12:56
Posts: 1396

  M roadster S50
Location: Leeds

Re: Lambda exhaust sensors

Post by Deano1712 »

Your o2 voltages look ok. 0.45 is lamdba 1. It seems to be controlling the mixture within limits. Fuel trim malfunction sounds like the trims are beyond permitted range. There is something causing the engine to demand more or less fuel than it expects to get the mixture right. I would check for induction or exhaust manifold air leaks.

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s3quattro
Joined: Sat 11 Sep, 2010 18:45
Posts: 7

  Z3 roadster 2.8
Location: Portadown

Re: Lambda exhaust sensors

Post by s3quattro »

My Z3 2.8 was built on the 11th January 1999 and first Registered on the 5th April 1999. Just 12 weeks from build to on the road.

S3quattro
Zed Carer
Joined: Thu 13 Dec, 2007 20:27
Posts: 1642

  Z3 roadster 2.8
Location: Wakefield

Re: Lambda exhaust sensors

Post by Zed Carer »

I had a play with RealOEM last night and managed to find the following:

Started with: Z3 / Roadster / 1.9 / Europe / RHD

03/1996 to 12/1997 - M44 16v (RHD & LHD)
01/1998 to 08/1998 - M44 16v (RHD & LHD), M43 8v (LHD only)
09/1998 (start of 1999 model year) to 04/1999 - M44 16v (RHD & LHD), M43 8v (RHD*** & LHD)
05 /1999 to end of production - M43 8v (RHD & LHD)

*** start of production of 1999 models overlaps with the end of the previous (M44) model. There were no RHD M43 8vs manufactured before 09/1998.

All 1.9s from 05/1999 were M43 8vs and the 2000 model year vehicles (start of production 09/1999) appear to have involved only the cosmetic changes; e.g. clear indicators, etc. For the M43 8v RealOEM shows the following

REGULATING LAMBDA PROBE L=370MM Part No 11781247406 (Pre-CAT)
LAMBDA PROBE L=450MM Part No 11781743996 (Post-CAT)

RealOEM does not show any changes to the exhaust system on the M43 from 09/1998 to the end of production and both the M44 and the M43 had 2 Lambda senors that look to be common between both models; i.e. same Part No.

As already suggested I'd look at the air intake pipes and make sure that everything there is OK first as unmetered air entering the engine can cause unreliable readings - there is a small pipe on the M52 that quite a number of members have had problems with as the cars get older.
Hers: Z4 2.0i Sp --------------------- His: Z3 2.8
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Lambda exhaust sensors

Post by colb »

Thanks for all the info so far, have had another look at my live data thgis morning.

Seems theat long term fuel is stuck at a reading of 19.53
Oxy sensor Bank 2 (after Cat reads 0.43 to 0.49 at tick over and 2000 revs
Bank 1 sensor seems ok ranging up and down and gives a good wave form on my scanner.

Can't find any air leaks under the bonnet

MAF air flow reads 5.38 at 800 revs tick over
7.94 at 2400 rpm

Any opinions on these lates figs?

Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
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colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Lambda exhaust sensors

Post by colb »

Update on my problem with Long Term Fuel Trim stuck at 19.0 on my Engine Check software.

Tried cleaning the Maf which finished it off completely, no longer putting a signal out.

Replaced Maf with a pattern part and Bingo, Fuel Trim now responding and car pulls like a train.
May still explore the exhaust sensors as they seem a little lazy.

Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
Zed Carer
Joined: Thu 13 Dec, 2007 20:27
Posts: 1642

  Z3 roadster 2.8
Location: Wakefield

Re: Lambda exhaust sensors

Post by Zed Carer »

I agree that using the VIN is the best way but there can be other issues with RealOEM. I needed a new battery retaining clamp and bolt, it is shown in the relevant diagram but was not included in the list. Phone the my local dealer who had the same problem; i.e. could see it on the diagram but no Part No shown. A couples of hours later he phoned back and the explanation was that it was now a Special Order item and that is why the Part No was not showing!!!!
Zedonist wrote:Model year 2000 M43 Engines badged as 1.9 will have 2 Lambda sensors.
Just checked the documentation for our first Z3 (model year 2000), build date Feb 2000, first registered May 2000. The brochure refers to 1.9i but the Invoice shows Model: Z3 1.8 Roa and it was badged as 1.8 - putting the VIN into RealOEM does show 2 sensors.
Hers: Z4 2.0i Sp --------------------- His: Z3 2.8
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