----- Original Message ----- From: "S.Harrison" <diverseimaging@EARTHLINK.NET> To: <vanagon@GERRY.VANAGON.COM> Sent: Monday, April 14, 2003 9:02 PM Subject: 82 Failed CA Smog Test- help!
> 82 Vanagon Westy. 89K on original engine. > > Took it to a local garage that is certified to smog test vehicles up for the > CA biennial inspections. Drove it for a about 2 hours prior so it was good > and warmed-up. > > I passed all aspects of the test but the CO% at idle -- I was at 5.56%, with > a maximum allowable of 2.00. The CO% at 2500 RPM measurement was fine, about > 0.62%. > > So what could help? I'll be changing the oil and filter, installing new > plugs, cap, rotor, and points before the next check, but any ideas on how I > can lower the CO percentage? > Could the AFM be at fault? Yes. > Leaky injector seals? Yes. All you mention, and much, much more could be the source of your problem. You're on the right track by first making sure the ignition system is in tip-top shape; be sure and set the timing and idle while you're at it. You might also set the idle at the top end of the specified range since increased RPM's tend to help here. Next, start checking things: fuel pressure, injector seals, leaking injectors (including cold start), TempII sensor, and so forth. All these things can be checked using fairly simple tools and equipment. The AFM is a little tougher since you don't have (I'm guessing) an O2 sensor. Over time the spring in the AFM weakens, leading to richer running. It can weaken so much that even adjusting the idle mixture control full lean won't be enough. The spring inside the AFM can be tightened to compensate and that's usually accomplished by monitoring the O2 sensor output as you tighten until you get it back into the right range. I suppose if you're using a "pass or don't pay" sort of place you can just keep trying until you get it right, but it might be better to take it to a shop with an exhaust gas analyzer (make sure they use the port, not the tailpipe) and have them set it correctly after you've done everything else. --------------------------------------------------------------- Tom Young '81 Vanagon Lafayette, CA 94549 '82 Westfalia --------------------------------------------------------------- |
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