Bizarre idle / Weak idle when starting

[ParkerRocker]

i have noticed over the past few days that my idle has become extremely odd when starting up the ex. Today it was shaking between 500 and 1500 rpms for a good 30 seconds after start before it settled into its normal range.

i replaced the air filter (old 1 was a brick), and this seems to have solved the problem.

However since it was not consistent i am still hesitant to declare the problem as fixed. Does anybody have any ideas?

 

[manaen]

a few things to check,
1) clean the MAFS use some CO MAF cleaner to spray over the tiny wires inside. It may look clean, but any little bit of dirt will greatly effect it's performance. I clean mine about once a month to ensure the best fuel mileage
2) check and clean the IAC make sure it moves freely and is clean of all carbon
3) run a vacuum test on the engine and see if things are up to speed
4) could be time for a seafoam treatment to clean out the carbon in the upper inkate.
5) when was your last tuneup?
6) any codes pop up?

 

[ParkerRocker]

MAF has been cleaned, i just seafoamed it 4 days ago.
How would i vacuum test it? and where is the IAC?

It's fully tuned up and now that u mention it, i did see the CEL while i was on some rough terrain the other day. but i didnt see it after so i assumed that the rough terrain was throwing off a false reading.

 

[manaen]

The IAC (Idle Air control) Module is located close to the throttle body. It is a cylindrical shaped solenoid valve with a 2 wire connection coming from it's base. It is normally held onto the intake with 2 bolts. It is how the computer adjusts the idle of the engine. They are fairly inexpensive to replace and can be picked up at most parts places.

do a search on here for vacuum test and you will probably find about 300 threads on how to do it.

 

[ParkerRocker]

It was the IAC, i pulled it off, removed the valve from the sensor and hit it with some brakeleen. all better! :

 

[manaen]

generally once they start to go screwy they need to be replaced soon. Luckily they are not too expensive. Hopefully the cleaning will last you a while.