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excelc *
Age: 56 Zodiac: Joined: 24 Nov 2012 Posts: 23 Location: bexley
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Posted: Sat Mar 28, 2015 15:44 Post subject: MAF / AIR MASS SENSOR |
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This maybe a daft question, but where is the air mass sensor located on my 3.2 did ??? , I know what it looks like but cannot locate it. ?? |
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Google Sponsor
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Posted: Sat Mar 28, 2015 15:44 Post subject: Google Ads keep the POCUK free to join! |
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radiomike ******
Joined: 04 Aug 2010 Posts: 1483 Location: North Bucks
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excelc *
Age: 56 Zodiac: Joined: 24 Nov 2012 Posts: 23 Location: bexley
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Posted: Mon Mar 30, 2015 10:01 Post subject: |
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Ah yes that's it( ebay item) , but it doesn't look like any air mass I have seen this looks more like a temperature sensor . |
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rich r ********
Age: 50 Zodiac: Joined: 11 Sep 2009 Posts: 5332 Location: Selby, North Yorkshire
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Posted: Mon Mar 30, 2015 11:34 Post subject: |
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There are different types of MAF sensor - the most common being the hot film type like this one. It's simply a very fine conductive film that sits in the air flow. The current flowing through it is proportional to the speed of air passing over it. There's also a thermistor in the same package to measure the temperature of the air at that point. The two readings can be used to calculate the mass of air entering per second (as the density of air changes depending on temperature). |
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excelc *
Age: 56 Zodiac: Joined: 24 Nov 2012 Posts: 23 Location: bexley
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Posted: Mon Mar 30, 2015 12:50 Post subject: |
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Hi , thanks for the reply, am I correct in thinking there should be a wire filament running across this housing ?? |
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rich r ********
Age: 50 Zodiac: Joined: 11 Sep 2009 Posts: 5332 Location: Selby, North Yorkshire
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Posted: Mon Mar 30, 2015 13:27 Post subject: |
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No, it'll be about 5mm long (if that), and housed inside the plastic bit that protrudes into the tube. You can't quite see it on the photo in the ebay advert, but the connector is at the other end of it. |
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trekker ********
Age: 83 Zodiac: Joined: 25 Jun 2012 Posts: 5202 Location: Zimbabwe
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Posted: Mon Mar 30, 2015 14:13 Post subject: |
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And for those who have these on the trucks, how are they tested, resistance measure, continuity ? And the conductive film ? |
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excelc *
Age: 56 Zodiac: Joined: 24 Nov 2012 Posts: 23 Location: bexley
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Posted: Mon Mar 30, 2015 15:38 Post subject: |
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I was going to ask that question ?? How do you test them ???? |
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rich r ********
Age: 50 Zodiac: Joined: 11 Sep 2009 Posts: 5332 Location: Selby, North Yorkshire
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Posted: Mon Mar 30, 2015 15:55 Post subject: |
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The problem with most hot wire or film MAFs is that they tend to fail by becoming less accurate rather than outright failure. So although the ECU will flag if it returns a voltage that's clearly unexpected (eg indicating huge airflow when the engine is at idle for example), generally they just become slower to react to changes or fail to indicate the flow properly at one end of the range. The voltage they return may well be reasonable, but indicate less air is flowing than actually is - leading to the ECU possibly injecting an incorrect amount of fuel (though this all depends on how the ECU uses MAF data and other data such as from exhaust oxygen sensors or manifold pressure sensors)
So testing is generally a case of substitute with known good, rather than absolute measurements - as you'd need another way of measuring the air flow and temperature at that point in the intake system to compare - in other words, a known good MAF |
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VIKI *****
Age: 45 Zodiac: Joined: 08 Jun 2010 Posts: 846 Location: swansea
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Posted: Mon Mar 30, 2015 20:02 Post subject: |
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Is that air flow sensor will be before or after air filter housing? In V78 3.2 4M41 01' model? |
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rich r ********
Age: 50 Zodiac: Joined: 11 Sep 2009 Posts: 5332 Location: Selby, North Yorkshire
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Posted: Tue Mar 31, 2015 9:33 Post subject: |
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After air filter - you don't want leaves and dust hitting sensitive electronic sensors |
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VIKI *****
Age: 45 Zodiac: Joined: 08 Jun 2010 Posts: 846 Location: swansea
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Posted: Wed Apr 01, 2015 5:32 Post subject: |
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THX rich |
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magn1t ***
Joined: 07 May 2006 Posts: 153 Location: NZ
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Posted: Wed Apr 01, 2015 6:26 Post subject: |
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That's the IAT sensor.
Do they even have an airflow sensor?
Have you read the service manual? |
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RogerStenning *
Age: 59 Zodiac: Joined: 24 Aug 2019 Posts: 24 Location: Bromley area
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Posted: Mon Sep 16, 2019 14:20 Post subject: |
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On '07 onwards, with the 4M41 engine (3.2 common rail diesel), the MAF Sensor is located on top of the air intake filter housing. Open the bo net, as you face the front of the car, this is located the left of the engine bay. It's the big black plastic housing. The MAF Sensor is on the right of the top of the housing, just prior to the air hose, as part of the top cover of the air filter housing.
Edited to add diagram. The MAF Sensor on 4M41 engines is item 8 on the diagram. |
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StronsayShogun Newbie
Joined: 12 Jan 2020 Posts: 9 Location: Essex
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Posted: Mon Jan 20, 2020 19:42 Post subject: Buying a MAF? |
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Anybody have a link for a MAC purchase? |
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