1987 Suzuki Samurai Smog Test / Spark plug temp. Range

DIJITWRX

MEMBER
1987 SUZUKI SAMURAI

Engine Performance problem
1987 Suzuki Samurai 4 cyl Four Wheel Drive Manual 135K miles

87 Suzuki Samurai failed CA smog test with a fresh head, plugs, cap, rotor and timmed to perfection. HydroCarbon count was 54 points over the allowable limit (rich mixture/un-burnt fuel) everthing else passed... The Hitachi Carb is preset at the factory, one must remove the carb and remove a set pin in order to make any adjustments to the mixture.

The question: If I install a "hotter" spark plug, will this aid in burning the excess fuel and reduce the HC level seen at the smog station and thus "possibly" passing?

Thanks,
- - - Dave

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Hydrocarbon failures mean unburned gasoline is passing through the engine and entering the exhaust. The three most common causes include ignition misfire, lean misfire and low compression (typically a burned exhaust valve). Ignition misfire can be caused by worn or fouled spark plugs, bad plug wires or a weak coil. Lean misfire results where there is too much air and not enough fuel, so check for vacuum leaks, dirty injectors or a fuel delivery problem. In addition to these, hydrocarbon failures can also be caused by oil burning due to worn valve guides, valve guide seals and/or rings.