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high co at idle 200 1981

posted by  NCH on  Sat Mar 13 10:44 CST 2004
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I have an ’81 245 GLT wagon with B21F and CIS fuel injection.
I recently failed emissions due to high CO at idle (1.2-1.4%). I have checked the usual suspects, I have cleaned the TB, replaced fuel injectors, filters, checked for vacuum leaks, set the timing, replaced oxygen sensor, and reset the idle and throttle switch.
I have noticed that the frequency valve is not buzzing at idle. Voltage is present at idle (9V) to the frequency valve and the valve has 3 ohm resistance measured at the terminals. When I increase the rpm or induce a small vacuum leak at idle the frequency valve starts cycling, voltage to frequency valve goes to 12V, and the CO drops like a stone.
I am considering adjusting the CO screw at the AMM. One problem is that I can’t seem to engage the screw through the small access hole (although I can poke around and affect the co with the 3mm Allen).
Any advice would be appreciated!





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New high co at idle [200][1981]
posted by  NCH  on Sat Mar 13 10:44 CST 2004 >


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