Rough running, idling, and shifting issue. Please help! - Toyota Yaris Forums

IndestructibleYaris · 11-27-2021, 01:44 PM

To identify a performance issue, add fuel or subtract fuel and see what happens. Do a cylinder drop test. You're gaining clues as to whether it's fuel, spark, compression, or timing related. Since you have a code for intake air valve I'd go there first with a diagnosis. I'm sure you can test the idle air control valve with just a battery and some wire. You can cause a vacuum leak and see if it improves, if so I'd just gamble with a new iac

11-27-2021, 01:44 PM	#3
IndestructibleYaris Drives: 2007 Toyota Yaris Sedan Join Date: Feb 2019 Location: Harrisburg, PA Posts: 149	To identify a performance issue, add fuel or subtract fuel and see what happens. Do a cylinder drop test. You're gaining clues as to whether it's fuel, spark, compression, or timing related. Since you have a code for intake air valve I'd go there first with a diagnosis. I'm sure you can test the idle air control valve with just a battery and some wire. You can cause a vacuum leak and see if it improves, if so I'd just gamble with a new iac