View Full Version : Voltage for 14.7 stoichiometric

04-14-2002, 05:45 PM
Was looking around the web for Air/Fuel ratio gauges and found a web site that sells a few, one of which is a simple voltmeter type. www.gadgetseller.com (http://www.gadgetseller.com)
So this made me wonder if anybody knows what the voltage reading should be at 14.7 for a VW Golf GT (Same RD engine as GTI).

#53 ITB Golf GT

04-15-2002, 11:41 PM
Connect a high-impedance voltmeter to potentiometer terminal # 17. With the sensor plate in the rest position the voltage should be 0.2 to 0.3 volt. As the sensor plate is lifted, the voltage should smoothly increase to about 7.0 volts.
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Glad to be of help

Eric Parham
04-16-2002, 01:31 PM
The A/F ratio gauges generally use an O2 sensor. The voltage output should be around 0.5V for 14.7 stoch, about 0.7V for a fatter/richer mix. Only a digital voltmeter or multimeter may be used to measure it. The range is 0.1 to about 1.0 for a good O2 sensor (and some work better than others). Get as close to the O2 sensor as possible to find a good ground (the head usually works well).

Eric Parham
04-17-2002, 03:23 PM
Ahhh, perhaps I misunderstand the original question! The current (not voltage) to the grey plastic thingy (differential actuator) attached to the silver fuel distributor (CIS-E only) should be about 10 milliamps IF your O2 sensor is working and IF your mixture is properly adjusted.

There was a misprint in one of the Bentley manuals that indicated an INCORRECT 6 ma. However, this is NOT a direct measurement of A/F ratio. It's just a check that the system is set to spec so that it has some leeway left to auto-adjust for richer and/or leaner transients.

04-18-2002, 04:30 PM
My understanding is that its more like .75. I can't say that I read this in a publication tho. Just info I got from talking with people at vwvortex.com. Does anyone have this info in print somewhere?


ITB Rabbit