Beware - Aftermarket MAF

UK forum for general and technical discussion about the Z3 roadster
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BonBon
Joined: Tue 08 Jan, 2008 21:10
Posts: 1227

  Z3 roadster 1.9

Beware - Aftermarket MAF

Post by BonBon »

I'm on a long term project to see how I can improve on my 10km/l on my 1.9L M44 Auto. I think a few years ago it was 11-12.
I have relatively new Camshaft and Crankshaft Sensors - so I'm thinking MAF and Lambda.
I have new aftermarket MAF lying around which I bought a few years ago on a whim. I gave it a shot. Anyway - the car car drove OK, but lost the little oomph it had and throttle response was in the bog. In addition, on two tanks of gas the aftermarket MAF (pictured below) consistently gave 10% lower fuel economy at 9km/l.
My MAF is the original - now at 318,000km. Would a new one improve power and fuel economy :shrug
Is it possible to gauge it's health? It does not trip any codes. Cleaning the MAF or higher octane fuel did not impact the fuel economy or driving "feel".
BTW - Does anyone have any experience on the effect of a old lambda specifically on fuel economy (mine is a 4 year old OEM ~100,000km)?
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Last edited by BonBon on Wed 12 Aug, 2015 14:34, edited 1 time in total.
John Wilson
Joined: Fri 12 Jun, 2009 12:11
Posts: 252

  Z3 roadster 2.0
Location: Diss

Re: Beware - Aftermarket MAF

Post by John Wilson »

You have to be really careful cleaning the MAF. You can get a aerosol type cleaner specially for them so you dont have to touch the wire with anything. I know someone at a Z outing tried cleaning one and ended up having to complete the run by disconnecting it completely. Cant remember who it was. Think it was up in Yorkshire. Happy days!
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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: Beware - Aftermarket MAF

Post by colb »

Never use aftermarket Mafs, total wast of cash, been there done it etc.
Same for Lambda sensors, use good make like Bosch.

Have you the ability to put the car on diagnostics and see what the lambda sensors are doing in live data, you would at least see if they are responding as they should or getting slow.

Colb
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
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BonBon
Joined: Tue 08 Jan, 2008 21:10
Posts: 1227

  Z3 roadster 1.9

Re: MAF/Lamda & 1.9L Auto Fuel Economy

Post by BonBon »

Just to close the loop - changed out to new Bosch MAF and Lamda* - and no change in fuel economy - getting consistently 10km/l. The type of fuel, % inner city driving and use of AC are the biggest factors......
*There was no reason to suspect my old OEM ones - just age.
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lightning
Joined: Tue 27 Nov, 2007 08:15
Posts: 818

  Z3 roadster 3.0i
Location: Stockport

Re: Beware - Aftermarket MAF

Post by lightning »

That fuel economy is about right for a Z3 Automatic, in town driving. Using the aircon can reduce economy by 5-10%
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BonBon
Joined: Tue 08 Jan, 2008 21:10
Posts: 1227

  Z3 roadster 1.9

Re: Beware - Aftermarket MAF

Post by BonBon »

The only problem is that I'm talking about sub-urban most at 100km/h.
Inner city I would do closer to 9km/l.
But what's another 150 quid thrown into this 326kkm barrel of fun ;-)
deni2s
Joined: Mon 25 Mar, 2013 22:02
Posts: 761

  Z3 roadster 2.8

Re: Beware - Aftermarket MAF

Post by deni2s »

You can try to chiptune ignition timing for higher octane, by default it is chiptuned for 91-95, so using 98 without chiptune will not give expected improvement.
Also try to reset adaptations and see what happens then.
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BonBon
Joined: Tue 08 Jan, 2008 21:10
Posts: 1227

  Z3 roadster 1.9

Re: Beware - Aftermarket MAF

Post by BonBon »

How do I 'reset adaptations'
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
Posts: 2225

  Z3 roadster 1.9

Re: Beware - Aftermarket MAF

Post by BladeRunner919 »

You have to do it in inpa/carsoft/dis.
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