Engine Management Light after Service

AquariusTony

Regular Member
British Zeds
Joined
Mar 18, 2020
Points
14
Location
East Yorkshire, England
Model of Z
1.9 Z3 Roadster
Thanks for your advice guys.

Just an update.

I ran the car yesterday and it almost stalled and the engine felt like it was going to just out, it was juddering and vibrating that much. I unclipped the power clip to the MAF and it worked fine.

Cheers,
Tony.
 

colb

Zorg Guru (V)
British Zeds
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Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
Seems like you found the problem, disconnecting the Maf will make the car run on default settings, hence it ran better when you unplugged it. You could try cleaning the Maf but I doubt that will sort it, bite the bullet and put a new ine on there. Only go for a oem replacement Bosch or Seimens, don't waste your money on cheap ebay items, you will end up paying twice, been there done that in the past. The high fuel trims would seem to be caused by the Maf malfunctioning and misreporting the volume of air entering the engine hence the EML when the mismatch is picked up at the exhaust sensors.
 

mrscalex

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MAF well be knackered. But I'm still suspicious about air leaks due to intermittent nature from prodding things.
 

AquariusTony

Regular Member
British Zeds
Joined
Mar 18, 2020
Points
14
Location
East Yorkshire, England
Model of Z
1.9 Z3 Roadster
Hi everyone,

I’ve just fitted the Bosch MAF, and my car runs now. But now my car is slightly juddering and it also smelt like rotten eggs for short time.

It’s one thing after the other at the moment.. :(

I’ve attached the live data.

Tony.
 

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mrscalex

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The short term fuel trims are way off.

There's a possibility it needs a run to reset the adaptations (state of tune) but I'd tend to think not.

My money is still on an air leak hiding somewhere. It could be something else of course but that's still my first port of call.

Others may see something else in the diagnostic values I'm missing. Which I have to say is fantastic you are providing these - generally a lot more guessing is involved as it's unusual people have this insight.
 

AquariusTony

Regular Member
British Zeds
Joined
Mar 18, 2020
Points
14
Location
East Yorkshire, England
Model of Z
1.9 Z3 Roadster
The short term fuel trims are way off.

There's a possibility it needs a run to reset the adaptations (state of tune) but I'd tend to think not.

My money is still on an air leak hiding somewhere. It could be something else of course but that's still my first port of call.

Others may see something else in the diagnostic values I'm missing. Which I have to say is fantastic you are providing these - generally a lot more guessing is involved as it's unusual people have this insight.
Yes I noticed that the fuel trims were way off (I’m learning now haha :D). I’ll take it for a spin later and see if it resets. It’s worth a try I suppose

I’ll have another look for the air leak too.

Regarding the images of the codes that I’m providing, I’m just trying to make it easier for everyone so I can get it sorted!! I’m glad you appreciate it.

Tony.
 

colb

Zorg Guru (V)
British Zeds
Joined
Nov 25, 2012
Points
178
Location
Newport, South Wales,UK
Model of Z
Z3 M43 1.8 (1999) and Z4 E85 2.5 (2003)
Probably an air leak causing the fuel trims to reach their max level to trigger the EML. The -20 on your STFT would indicate its reporting a lean mixture being seen by the O2 sensor, since you put a new Maf in I would suggest you clear the code and reset the adaptions so you start with a level playing field to investigate further if that dosn't clear it. If you can't visually find any leaks best bet will be smoke testing it or trying to spray brake cleaner around the rubber componants on the engine, if the engine picks up when sprayed it will pinpoint the area where it entered the system. Try this from the engine side of the Maf qall the way to the exhaust, include the cam cover joints around the head.
 
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