Exhaust Hydrocarbon Measurement for Tuneup Diagnosis? 660105

With an activated exhaust control program in California and its imminent prospect nationwide, recently attention has been focused on simplifying exhaust hydrocarbon measurement for potential use as a tuneup garage diagnostic tool. Work has been underway to evaluate new instrumentation and procedures for hydrocarbon measurement suitable for field use. It is concluded that:
  1. 1.
    With a “one minute” cycle, measured emissions seem to correlate adequately with the California procedure.
  2. 2.
    There are prototype instruments which are inherently much less susceptible to environment of use.
  3. 3.
    For engine diagnostic purposes, the principal uses of hydrocarbon measurements would be: An initial check- almost any engine malfunction raises hydrocarbons; hence, if low, engine does not need tuneup work. Recheck after tuneup-an increase in hydrocarbons indicates a tuneup oversight or error, and the car would then be checked further.


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