VW Golf R32 Forum banner
1 - 5 of 5 Posts

66 Posts
Discussion Starter · #1 ·
Ive been searching the internet for a while now and im not able to find out much information about the Resistor that VF- Engineering Say MUST be Installed on the black wire of my MAF Wiring

but i wanted to find out a bit more about this resistor I need to find out how something works and why I am doing something just for peice of mind so ive been doing a bit of reading and heres what I can work out. I dont know a lot about Electronic Fuel Injection but here goes and im hopng someone could either confirm or correct me if im wrong....

It's Bosch 5 wire MAF Sensor with IAT Sensor
and On my 2003 R32 this is wire coulors and what I think they do

Pin Number Coulor Routing Description
Pin 1 Purple+Green -> ECM skt 26 IAT Signal
Pin 2 Blue+Yellow -> Fuel Pump 12v Supply voltage
Pin 3 Green -> ECM skt 27 Signal ground
Pin 4 Red+Purple -> ECM skt 53 5v Reference Supply
Pin 5 Black -> ECM skt 29 MAF Output

So if that resistor is fitted to the black wire it is lowering the Voltage Readings going back to the ECM from the MAF Sensor ?

if so why would it be trying to tell the ECU there is less air going through than is actually true ?

.:R32OC Site Contributor
4,848 Posts
I think the lower the voltage the more air so it would be telling the ecu you have more air going through although i dont know why you would want to do this either. prob best asking them? www.uk-mkivs.net or www.vwvortex.com will have info on the maf but i dont know if they will be able to tell you the reasons behind the resistor.

66 Posts
Discussion Starter · #5 ·
it's still running a stock fuel system apart from a 5 BAR Fuel Pressure Regulator

The C2 Motorsports Fueling Upgrade Runs all these modifications and no resistor in the wiring

6- Genesis 415cc injectors
6- Injector harness
C2 95mm MAF housing
4"-3" Silicone reducer
4" open element filter
C2 400 Flashload software

and I think it is stuowen on here runs a VF Stage 2 with AMD Software and no resistor.

I wont be running the car untill I have my Air/Fuel Ratio Gauge Installed just to make sure it's fuelling correctly.

reading a bit more...

more air = cold wire (more cooling) = less resistance = high voltage output
less air = hot wire (less cooling) = high resistance = low voltage output

so for eg the engine would normally work on a range of 0v - 5v say if you force feed it air all the time it will always be cooling the wire more so your voltage output would be higher might always be working on the higher end of the scale maby from 5v - 10v

by adding the resistor you are acting like there is less air and keeping the voltage in the range of 0v - 5v ?

that sound about right ?
1 - 5 of 5 Posts