idle question

[henstepper]

What would generally cause a car to splutter/vibrate when in drive and reverse, but idle fine in park and neutral?

Also there is a slight dip in rpm when you put it into drive from park

 

[Immortality]

Idle has it's own tables in the tune. I would expect a slight dip as load comes on and off going from park to drive/reverse etc the IAC is there to control/maintain the idle speed so I would say that is working correctly.

 

[PlenumBiscuit]

see video above, pull out your IAC (2 screws), check if its gunky, clean it or buy a new one

 

[VP1993]

Have you done a service lately? Changed the spark plug and leads?

Had a similar problem with my VY and thought it was the IAC, I cleaned it and then replaced the motor - still the same problem

It ended up being an intermittant lead

Just a thought