Mechanics

ENGINE RUNS ROUGH IN THE MORNING

1994 Toyota Cressida

Engine Performance problem
1994 Toyota Cressida V12 Front Wheel Drive Automatic 138000 miles

My car engine runs rough in the morning. The rpm is higher than normal. The engine sounds louder than normal. However, after running the car for 15 to 20 minutes the car is smooth again. The rpm becomes normal. I ve changed the spark plus, plug cables, alternator and battery but the problem is still there each morning.
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Paul Lee
March 3, 2010.



Engine running rough or misfiring can be cause by the following-inspect and test all the following below: 1. Defective spark plug.
2. Inadequate spark/coil, defective spark plug wire.
3. Lack of compression
4. False air leakage.
5. Faulty fuel injectors.
6. Insufficient fuel pressure.
7. Contaminated fuel.
8. EGR valve that is leaking.
9. Oxygen sensors.
10. Idle air control valve.
11. Throttle position sensor.

Rasmataz
Apr 20, 2010.