Air Flow Meter made with resistors, seems subpar?

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jamhops
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Air Flow Meter made with resistors, seems subpar?

Postby jamhops » Wed Apr 18, 2012 6:43 pm

I bought a third party air flow meter which upon looking in the tube is made up of 2 resistors, (they have there colour code on etc) these seem sub par items as I cant see this functioning correctly? I also fell upon testing it for a few days it isnt having the expected effect on my mpg as the working afm should...

Wondered peoples thoughts on this as if I am right (this wont function as it should) then I am rather annoyed after the item was delayed 2 weeks?

Thanks
Renault Megane II 54 Plater 1.5dCi 100

davelowe
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Re: Air Flow Meter made with resistors, seems subpar?

Postby davelowe » Wed Apr 18, 2012 9:46 pm

What engine, and what are you expecting to achieve? Depending on the design of said meter, a resistor will simply supply a different current/voltage to the ECU. The parts probably cost less than a penny a piece.

I haven't consulted the manuals, but I would imagine that an air flow meter would incorporate a potentiometer....

Any links as to where you got it from?

The resistor colours determine their values and quality.
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jamhops
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Posts: 77
Joined: Sat Mar 12, 2011 1:34 pm
Currently Drives:: Renault Megane 100 1.5DCi
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Re: Air Flow Meter made with resistors, seems subpar?

Postby jamhops » Thu Apr 19, 2012 3:49 pm

davelowe wrote:What engine, and what are you expecting to achieve? Depending on the design of said meter, a resistor will simply supply a different current/voltage to the ECU. The parts probably cost less than a penny a piece.

I haven't consulted the manuals, but I would imagine that an air flow meter would incorporate a potentiometer....

Any links as to where you got it from?

The resistor colours determine their values and quality.



Item is from the bay number: 150783551183
I know that the resistors will most lightly just trick the ECU into thinking it is receiving a valid single from the Maf and I would assume nothing more, If I wanted to trick the ECU then I could do this myself :p

I will try take a picture of both the original part and the replacement, as far as I see there is no potentiometer the original was made of a thin wire (not copper) I was told it was a expensive wire that would resist as air flows over it and cools down... which I dont see how an insulated resistor could do anything like the same job... not sure it should even be sold as an Air flow meter.
Renault Megane II 54 Plater 1.5dCi 100

davelowe
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Re: Air Flow Meter made with resistors, seems subpar?

Postby davelowe » Thu Apr 19, 2012 9:55 pm

Ah yes - it is heated and then a thermistor measures the temperature drop based on the air flow past it. Probably Ni-chrome wire.

Are you confusing thermistors with resistors - I'm confused! Possibly the same set up with different thermistors?
Silver 08 plate 5dr 1.5dci Dynamique 106 Tech Run (re-mapped)

Red 03 plate 5dr 1.9 Dynamique dci120

Best advice for Megane owners: sell it before it bankrupts you!

jamhops
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Re: Air Flow Meter made with resistors, seems subpar?

Postby jamhops » Sun Apr 22, 2012 3:55 pm

Replacement (with resistors i think)
Image



Original (with thin metal strips)
Image


Does that make anymore sense now? Not sure I described it right before lol
Renault Megane II 54 Plater 1.5dCi 100

AlexB
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Re: Air Flow Meter made with resistors, seems subpar?

Postby AlexB » Sun Apr 22, 2012 4:05 pm

jamhops,

Let's start wit the beginning. What makes you think that the aftermarket sensor is better? Even if it is, then re-programming the ECU may be required, which is not trivial. If you want to investigate the issue, then look at the live OBD plots. Otherwise, just use the OEM part.
AlexB
(no, a different AlexB)

jamhops
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Re: Air Flow Meter made with resistors, seems subpar?

Postby jamhops » Sun Apr 22, 2012 4:12 pm

AlexB wrote:jamhops,

Let's start wit the beginning. What makes you think that the aftermarket sensor is better? Even if it is, then re-programming the ECU may be required, which is not trivial. If you want to investigate the issue, then look at the live OBD plots. Otherwise, just use the OEM part.


I dont think its better? I think the aftermarket isn't doing its job at all due to there being no increase in fuel efficiency (after replacing it from a genuine but faulty part) and looking at the part I don't see how it would be doing its job. Either way I don't see why reprogramming the ecu would be needed in any eventuality as it should be giving the same readouts as the original.

I wanted to investigate the 3rd party part before attempting a refund and ensure the part Is rubbish before complAining

I can not get readouts other then error codes arm as my Bluetooth orb has stopped functioning?..
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joeishmather
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Re: Air Flow Meter made with resistors, seems subpar?

Postby joeishmather » Sun Apr 22, 2012 5:07 pm

I thought that the airflow meter worked by running current thru the 2 thin wires which gave varying readings dependant upon air flow, I cannot see how the resistor set up will give anything but a constant reading.

Also what's reprogramming the ecu got to do with anything!? The part he's bought should be a replacement, patten part not original manafacture.. These parts should work the same as the oem ones and shouldn't effect the car in any way other than intended, therefor there will be no need at all to do anything with the ecu or anything else.

With regards the maf I would return it and complain, looks very poor and like I said I have no idea how tht could work!
Image

jamhops
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Re: Air Flow Meter made with resistors, seems subpar?

Postby jamhops » Mon Apr 23, 2012 3:56 pm

Thank you for confirming what I though, I thought I must be missing something but seems not lol
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AlexB
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Re: Air Flow Meter made with resistors, seems subpar?

Postby AlexB » Mon Apr 23, 2012 4:29 pm

This is exactly my point. If it is better, then it has to be different from the original...

It does not look better according to joeishmather, and it is still different. Not good.

jamhops wrote:
AlexB wrote:jamhops,

Let's start wit the beginning. What makes you think that the aftermarket sensor is better? Even if it is, then re-programming the ECU may be required, which is not trivial. If you want to investigate the issue, then look at the live OBD plots. Otherwise, just use the OEM part.


I dont think its better? I think the aftermarket isn't doing its job at all due to there being no increase in fuel efficiency (after replacing it from a genuine but faulty part) and looking at the part I don't see how it would be doing its job. Either way I don't see why reprogramming the ecu would be needed in any eventuality as it should be giving the same readouts as the original.

I wanted to investigate the 3rd party part before attempting a refund and ensure the part Is rubbish before complAining

I can not get readouts other then error codes arm as my Bluetooth orb has stopped functioning?..
AlexB
(no, a different AlexB)

joeishmather
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Re: Air Flow Meter made with resistors, seems subpar?

Postby joeishmather » Mon Apr 23, 2012 4:49 pm

I don't think he was hoping for it to be a better part as such or perform better than the original part, just better than the one that had broke... Im always wary when buying non original
Manafacture parts when it comes to electronics. Breaks and inanimate objects are more often than not fine, but electronic parts can cause further issues in my experience. Anyhow we live an learn!lol
One thing we are all now agreed on is that that maf you have bought is definatly not good!lol

Let us know how you get on sending it back for a refund.
Image

jamhops
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Posts: 77
Joined: Sat Mar 12, 2011 1:34 pm
Currently Drives:: Renault Megane 100 1.5DCi
Location: Portsmouth

Re: Air Flow Meter made with resistors, seems subpar?

Postby jamhops » Mon Apr 23, 2012 6:23 pm

joeishmather wrote:I don't think he was hoping for it to be a better part as such or perform better than the original part, just better than the one that had broke... Im always wary when buying non original
Manafacture parts when it comes to electronics. Breaks and inanimate objects are more often than not fine, but electronic parts can cause further issues in my experience. Anyhow we live an learn!lol
One thing we are all now agreed on is that that maf you have bought is definatly not good!lol

Let us know how you get on sending it back for a refund.


Will do, though I don't like using 3rd party parts but at £150 for genuine I had to try something cheaper...
Renault Megane II 54 Plater 1.5dCi 100

tomalamix
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Re: Air Flow Meter made with resistors, seems subpar?

Postby tomalamix » Mon May 07, 2012 11:28 am

why did you changed the flow-meter in first place? maybe you have a problem somewhere else...the mpg should increase after a faulty flowmeter is swapped for a good one, thats right, but the problem must be there.


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