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vmp hpx maf wiring
Posted: Mon Jan 16, 2012 12:24 pm
by gsracer
Does anyone have a pinout or diagram or can just share something as far as what wires go where with this thing?
I have on my motor
white shielded----- sensor input
black shielded---- ground
black white---12 volt
this is the pmas wiring diagram
Re: vmp hpx maf wiring
Posted: Mon Jan 16, 2012 1:21 pm
by bachig24u
Use 3,5 & 6, use signal return to Sensor GND or Chassis earth if you find instability with MAF signal.
Re: vmp hpx maf wiring
Posted: Mon Jan 16, 2012 1:27 pm
by gsracer
ok so then
ford # 6 to black white for power
ford# 3 to white shielded
ford#5 to chassis ground
leave the black shielded on the nissan side alone...?
Re: vmp hpx maf wiring
Posted: Tue Jan 17, 2012 12:40 pm
by gsracer
update.....
I think the problem lies in the ecu. The wiring is right.
I think the problem all boils down to the airflow. The stock maf reads .8 to 1 volt at idle, even with the engine chugging along at 400rpm it doesn't go below .8 volts.
With the hpx maf in the stock 3.5 inch piping at 800 rpms it reads .550 volts at the ecu then bounces to .080 (effectively off as far as the ecu is concerned) then back to .550 volts. I have tested directly out of the maf with a vdc probe and see .420-.450 volts when this happens.
Also when it does this it will trip a maf code in the ecu. However if i raise the idle to 1300 rpms it will read higher voltage function correctly and not trip a code in the ecu.
Ive gone back and forth from stock to the hpx, and the stock functions correctly, the hpx functions as well, i just don't think the stock ecu has the ability to resolve voltages below .550 volts even though there are tables for it in the ecu.
In the mean time it seems I'm stuck.
Either i go to a z32 maf and hope i don't max that.
or put the hpx maf in a 3 inch tube instead of the stock 3.5
Im sure the fact that this is in a blow through application doesn't help.
any thoughts on this are appreciated......
Re: vmp hpx maf wiring
Posted: Wed Jan 18, 2012 4:01 am
by Eric
not sure what ECU/car you are using this for, but some ECU's (eg. Z32) indeed have 0.5V as the minimum voltage hardcoded in the code that processes/translates the AFM voltage.
anything lower then 0.5V when the engine is running and the ECU assumes the AFM is defective and starts running in safemode.
-Eric
Re: vmp hpx maf wiring
Posted: Tue Jan 24, 2012 5:00 pm
by Matt
Been looking at this issue last week for Z32/Q45 code and its necessary to modify part of the code which checks for the 0.5v limit and reduce it
If you are using a Type 2 board would require reprogram to modify the ECU code. Let us know which model and email me and I can organise an update
Re: vmp hpx maf wiring
Posted: Tue Mar 15, 2016 1:07 am
by unkn0wn
Hi Guys,
today i put my HPX in, its a sr20det.
Wired the following to the correlating 3pin plug from the sr loom.
6 - 12v
5 - Gnd
3 - Maf out
i have not started the car yet....but i did test it.
no air state showd .795 to .8 V
blowing into the 3 inch tube registered a voltage increase, i think i saw 1.4v or so.
Just curious, should this be a lower output when there is no air, have i wired it wrong?
Re: vmp hpx maf wiring
Posted: Sat Mar 19, 2016 8:50 am
by Matt
Minimum with no airflow seems to be about 0.4V for Z32 and 0.8V seems right for the HPX
Minimum running voltage should be about 1V at idle (average normally about 1.1-1.2V)