My 280ZX failed the emissions test because of high hydrocarbons at idle. The car runs fine and passed the load test with flying colors. Thinking it may have just been a couple of dirty injectors causing a lean misfire I ran some mechanic in a can cleaner, changed the cap and rotor, but retest showed the same results.
The spark plugs are nearly white, the oxygen sensor light blinks as specified ... any ideas?
Rick
What kind of plugs are you useing? NGK BP6ES-II only. What were the CO readings? The O2 sensor on those models doesn't seem to -add- much fuel if they are WAY too lean, you may have to adjust the AF meter to get it rish enough to stop misfiring. Also if the timing is too high this can happen. My guess if the AF is adjusted too lean or there is an intake leak somewhere, like the boot at the throttle housing?
Got the right plugs installed, no leaks on the AF boot (checked with propane) ... sending it to one of the "state approved" mechanics so if nothing else will get a waiver.
Thanks very much for the information, we really do appreciate you taking the time to assist.
Rick
Again is sounds like the AF meter is adjusted too lean. These had pretty dumb computers and the O2 sensor was designed to lean out the engine, not very good at richening them up. We normally set them at like 2% CO before the cat with the O2 sensor unplugged and then let the sensor take it from there. Also make sure the throttle switch is working and adjusted right. Anyway hope the "State approved" shop has a clue about dealing with early FI cars, they aren't anything like the current models!
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