Thread: Chinese MAF

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OK it arrived today. It was packed well in bubble wrap in a cardboard box with no further ID.
It appears to have a resistor on one wire and a diode on the other.
It also has a mesh which AFAIR the VDO one doesn't have.( only the plastic grid which on this one is behind the mesh /ie before in the airflow )
Mesh is used to straighten the airflow to ensure it is consistent across the whole measured area, and is important of there is a bend within about 200MM from the sensor, so It looks that this is used on something else, Freelander I believe.
I will try it out when I get the chance.
Regards Philip A

It looks like a MAF signal emulator cos that resistor and diode can't work on the hot wire principle as the MAF should work... almost the same like the one in the link i posted in a previous post... i'd not use that on a Eu3 engine whatsoever, even if it was cheap IMO that money is wasted cos that sensor belongs to the bin

I later thought that the blue thing could be a thermistor which changes value with temperature.

If it were designed not to work why would they go to the trouble of fitting a mesh screen which looks to be the most expensive part of the whole thing?
I just had a look at Wiki and some youtube stuff and the appearance of the wires is pretty normal .

Regards Philip A

Originally Posted by PhilipA

If it were designed not to work why would they go to the trouble of fitting a mesh screen which looks to be the most expensive part of the whole thing?

Regards Philip A

probaby not made in a dedicated sweatshop, it might be left over mesh for the flour sifter making department so no extra cost to them.

Vee shall see!
I will try it out soon.
Zee proof of the pudding is in the eating.
Regards Philip A

What's certain is that the chinese MAF's construction is not like it should be

Originally Posted by ENGINE MANAGEMENT SYSTEM - TD5; 18-1-10 DESCRIPTION AND OPERATION

The MAF sensor works on the hot film principal. The MAF sensor has 2 sensing elements contained within a film. One element is controlled at ambient temperature e.g. 25 °C (77 °F) while the other is heated to 200 °C (392 °F) above
this temperature e.g. 225 °C (437 °F). As air passes through the MAF sensor the hot film will be cooled. The current
required to keep the constant 200 °C (392 °F) difference provides a precise although non-linear signal of the air drawn
into the engine.

Originally Posted by PhilipA

I later thought that the blue thing could be a thermistor which changes value with temperature.

If it were designed not to work why would they go to the trouble of fitting a mesh screen which looks to be the most expensive part of the whole thing?
I just had a look at Wiki and some youtube stuff and the appearance of the wires is pretty normal .

Regards Philip A

It is a thermistor.

I purchased an OEM MAF (priced the same as VDO MAF so I assumed wrongly that it was) from Rimmer Bros that ended up being a UK manufactured item with this arrangement. It looks very much like the one in your pic.

The MAF came with a calibration slip that gave error from 0 - 3910 mV. The resolution is 10mV and most of the errors are 0mV.
The worst error is 30mV at 3790mV. That is a 0.8% error which isn't too bad. The calibration stops at 3910mV so may well be worse higher up.

The company that makes the one Rimmer sells is SMPE.
SMPE - Manufacturing

​In cheaper alternatives the electronic signal output curves are often incorrect resulting in incorrect air to fuel ratios throught the rev range. SMPE has designed a custom microprocessor controlled circuit and each MAF unit is individually programmed as part of the manufacturing process to achieve consistent signals exactly matching OE performance. SMPE considers MAF production its flagship product improving the performance of Aftermarket sensors in the market. Each unit is individually calibrated, tested and has an individual serial number related test report.

Not something I'd buy as a first choice but it works ok.

I doubt a chinese knock off would have same process or QC as SMPE, so ymmv.

Well I fitted the $29 Chinese MAF and went for a test drive.

It may be my imagination but I thought the gearchanges were better than with my 5 year old VDO.

There were no quirks so far and the car drives better than ever. I gunned it over 20PSI up a steep hill and there was no dropout so unlikley that it is overreading, although I didn't take it to redline. These days I never have to take it redline as it makes so much more power around 2500-3000 RPM.

I will report if something goes bad , but I have kept my old MAF as a spare and will fit it if necessary.
I finally got to chuck my LR original MAF that was over reading and caused the ECU to drop out at high revs.

BTW the old VDO MAF does have a mesh screen, and has wires with no resistors on them but many including GM MAFs have the resistor and thermistor on the wires as with the Chinese one.
Regards Philip A