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I keep forgetting that this car has a handy schraeder valve test point, unlike the 240, where you need a specific adapter. I'll check that.
It does look like it could use an new O2 sensor. It appears to only switch between .2 and .7 volts, and it doesn't react very fast - even stutters a bit when falling to lean indication. Pulling the FPR line causes it to switch high, but it doesn't hold there when left off; it goes back to oscillating. Similar thing when pulling one of the small vacuum lines off the throttle housing - switches low, but then goes back to oscillating. It doesn't seem obvious from the FAQ, however, that the O2 sensor will cure my high NOX: "Airtex Automotive reports replacing degraded oxygen sensors has the potential to reduce a vehicle's emissions of hydrocarbons (HC) by 23% and carbon monoxide (CO) by 33%". According to this, the O2 replacement will likely improve the 2 items I already passed on, but doesn't mention the NOX improvement I need.
I have to say, that I'm still not confident in the methods defined for spotting vacuum leaks. With one small hose pulled off the throttle body, I hit the spigot with carb cleaner, and got no reaction. If I shoot it right down the spigot, then yes, I do get an obvious change, but I hardly trust that I would ever notice a typical small leak using this method. I'd prefer to do either a vacuum pump or pressure holding test for a more definitive result, but there's too many other factors/conditions that allow air to pass, and I don't know enough to design the perfect vacuum/pressure test.
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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto
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