Check engine light on. Changed plugs and oil. Still reads misfire cyl.3, 4, 6?

SHAWN C

MEMBER
1998 TOYOTA SIENNA
158,913 MILES

98 toyota sienna v6 3.0 idles fine ouiet accelerate sputters a few seconds, then kicks in to full power. Changed oil and plugs. Wires 2yrs old. Noticed on air intake left/passenger side, vacpump/booster?Was not opening each time gas was applied. Worked spring few times opened/w gas applied, but not all time?Doesnt this open port to allow fuel to all cyl. What else to check? Repair?What is the air intake part?Could it be this?Thank you for any info shawn c. Evansville, in.

Tuesday, January 31st, 2012 AT 5:12 PM

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Your 1st step here is have the computer scanned for codes and get back if any present-we start here

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Tuesday, January 31st, 2012 AT 5:15 PM

SHAWN C

MEMBER
2 POSTS

Computer codes read misfire cyl3, 4, 6
have fire in all cyl

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Tuesday, January 31st, 2012 AT 5:32 PM

RASMATAZ

MECHANIC
75,992 POSTS

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

1.Defective spark plugs

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.Throttle position sensor.

11.Manifold absolute pressure sensor

12.Mass Airflow Sensor

13.Idle air control valve

14. Camshaft and Crankshaft Positioning sensors-

Note: If it doesn't apply disregard it-

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Tuesday, January 31st, 2012 AT 6:52 PM