2002 4 Cyl Rough Idle
 

Trying to diagnose a rough idle on 2002 Camy

No CEL, does not stall, and runs well except for noticeable rough idle. Idle RPM~ 600.

Have done following:Cleaned MAF and throttle body, checked PCV, replaced engine temp sensor, checked spark plugs. To the extent I can have checked for vacuum leaks but not certain I understand a good method for this.

The idle has gotten rougher since I first noticed it 3-4 weeks back. My next step is to look at fuel pump/filter or injector - but looking for advice before I proceed.

Thanks for any comments.

JW

Was the battery discounted?

Are you needing to add coolant to the reservoir tank?

Vacuum leaks are just that. Typically holes, tears in vacuum hoses or intake air hose after the MAF sensor.

Try cleaning the MAF sensor. Use a throttle body cleaner. Check Utube videos on cleaning Toyota MAF sensor.

Thanks for the reply! Cleaned the MAF - twice before posting with no change. Battery is lass than a year old - I load tested after your reply and it checks good. Also no issue with coolant level. thanks for the help.