[urq] suddenly lean - the saga continues

Eric Renneisen racingiron at comcast.net
Wed Feb 14 21:58:18 EST 2007

Keith wrote:
> I don't think it's ecu, I feel sure it is purely 
> a mixture thing rather than timing. The air fuel 
> meter shows it to be a sudden leaning of mixture. 

If that meter is like the ones I've used that just display the voltage
signal from an O2 sensor (does your WR have an O2 sensor?), just because
it says lean, doesn't mean it is.  It just means that there's more
oxygen in the exhuast than expected.  The mixture could be fine, or even
rich, but if there's a misfire then the fuel nor the oxygen will burn,
which leaves extra O2 in the exhaust.  Just something to consider.

Have you looked at the plugs?  You could induce the problem on a
deserted road, then immediately shut the car off and coast to a stop.
Pull the plugs and read 'em the old fashioned way.

Eric R.
'86 urq
'93 urS

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