Mechanics

ENGINE HUNT

1999 Daihatsu Hyjet

Engine Mechanical problem
1999 Daihatsu Hyjet Two Wheel Drive Manual 120000 miles

I bought this car on year 2008, When the engine gets heated the engine start hunting. This will stop when the air conditioner ON. Also some times this problem not come. Please explained.
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Indika Silva
March 10, 2009.



Hi Indika,

When surging occurs, it usually is due to excessive air going into the intake manifold and following are possible causes.

1. Faulty Intake Air Control (IAC)valve. IAC stuck in open position or not closing due to clogged coolant hoses.
2. Vacumn leakage at intake manifold, could be due to dislodged hoses or faulty PCV.
3. Idling speed adjusted too high.

KHLow2008
Mar 10, 2009.