Bosch AFM pinouts

[blitzracing]

Ive just purchased on of the Chinese replica Bosch AFM's for bench testing to see if they work, and if not why not, but need the pin outs (same as the Bosch). There are 5 pins, 1) air temp, 2) +12 3) ground 4) 5v 5) Airflow. All I need to know which end of the five pins is pin 1, at the square or round end of the connector? It wont be connected on TVR installs as this pin is not needed, only 2,3,4,and 5. The AFM also needs a separate feed for 5 volts so I assume that an extra regulator is included in the wiring loom when connected to the 14CUX? Ready to go with the garden blower strapped onto a 5AM and the Bosch as we speak

Thanks

Mark

[BicesterGriff]

Pin 1 is the air filter end (air entry)
Pin 5 is the Engine end (air exit)

The +5 Volts is tapped off the TPS Supply

I bought A "Genuine AFM" From some Land rover Supplies Outfit, I could not get her to idle properly, she just hunted all over the place ie Rich / Lean / Rich / Lean all the time.
The "Genuine"afm did not have bosch written on it. I sent it back only to be advised that i was a TW*T and there was nothing wrong with it!.
I bought a Bosh MHK100800 from MA and all was fine

[blitzracing]

Thanks for the info. I should be able to tell pretty quickly if the output is unstable for given airflow or heat sensistive, but if the calibration is different to the genuine unit it may be possible to overcome this, as the voltages will have to be altered anyway if you want it to replace a 5AM without a remap. It was only £35 so I dont mind pulling it to bits......

[BicesterGriff]

Yeah I agree £35 is cheap enough. I Might get one just to see what its like.
Im just annoyed with some suppliers selling genuine afm's and quite obviously they are not... Is it all down to calibration??
Are the cheaper versions non linear, this would make sense on my car as it pulled like a train but would not idle.

[blitzracing]

You only have a single feed wire with a variable voltage depending on airflow, so it must be. If it wont tick over is likely the initial voltages are wrong, as the 14CUX is very sensitive to the seetings at idle. + /- 200 mv is enough to cause the mixture to go to over rich or lean. It becomes less critical as airflow increases.

[BicesterGriff]

How about putting 2 or 3 of these on a car in series and logging the output voltages? Just an idea

[blitzracing]

Ive got some readings for the "fake" now against a 5AM, and did it with a couple of vacume cleaners (up to a 2.5kw garden vac) with a variable speed controllers, and the AFM's piped with the same airflow, although I cant get above 4.5 volts even with the workshop like a wind tunnel!. Ive also now got Lucas 20 AM v's 5AM readings. The Lucas 20 AM simply reads about 10% lower than the 5AM across the cars usable range. (Its considerably different at no airflow, but that does not matter). I think it would be feasable to simply amplify the output in a linear way by 10 % to make the outputs tally, so you would not need to rechip if you fitted one. The Fake Bosch has a much higher output at low airflows, that then evens out to match the 5AM , and eventually becomes lower at high airflows. This is harder to match, and will require some more electronics and a "lookup" table to convert the voltages. I would still like to do a fake to real Bosch comparson if I can borrow one???

[BicesterGriff]

where do you live ill bring mine over!