Hello!

This is really the first time in 7 years my car has given me a problem and stumped me. It starts up just fine and sounds completely normal on a cold start but after a couple minutes of warming up it starts doing this idle thing where it will jump up and down by itself. For example, it's idling high cause it just started and then it will go up to about 2200-2300rpm and then back down, and back up, and back down, etc. until I turn the car off. I've tried to clean the IACV and that didn't help. We have had a TON of rain here lately, I don't know if a sensor or something got wet but I don't really know what to check. Any insight is helpful as I miss driving it and need to get it back to normal again. Thank you.

 

maybe someone you know can hook up an read the onboard.. get some measurements off the sensors and see..

TPS was my first thought... just don't like making thoughts without measurements

 

You could try a MAP whack and zip tie. I would also hunt for loose vacuum hoses.

 

Mine was doing that when I installed the IACV incorrectly. Might want to start there. Specifically the sensor that goes to the shaft. There is two notches it needs to fit between. Hard to explain really lol. S

 

Iacv or map

 

Mine did this when I stupidly forgot to plug back in the electrical plug at the back of the IACV after cleaning it once. Boy did I feel dumb when I found that plug sitting there unplugged. Check that connection.

 

From what I gather the Map Whack is nothing more than zip tying the sensor and connector tightly, correct? I did that, checked a lot of other connections too. IACV has been cleaned. I pulled the "Back Up" 7.5 fuse for a minute as well as someone suggested that, and also disconnected and reconnected the battery again. Let it start and it seemed like it took longer to start doing the up and down nonsense but it still did. I let it do it for a minute and it went down to normal for a couple seconds and then started back up again. After that I shut it back off and went inside cause my eyes were burning from the exhaust.

 

Stuck IAC rotary shaft, guaranteed.

Cleaning will not always work. Take it apart, and free up the rotary shaft with your fingers.

Using cleaner will make it worse sometimes, by washing carbon and crud down behind the rotsry window, the clearance is paper thin.