97 240 ka-t blah blah blah. anyways so i finally got my car tuned and running and after oh 30miles it threw a code P0505 for a iacv-aac. now on a 95-98 240 the iacv are different then a pre 95 so i am wondering what sensor i need to check. there is 3. i tested the red connector (which i believe is the iacv-aac) it should be 10 ohms i got 9.8. my car runs good all around but when it decelerates the rpms go down to 500 then go back up to +- 1000. i dont know if this has anything to do with the code or if it has to do with the sh!tty afc2. also the vacum on my boost/vac gauge is at like 25 or 30 at idle. does this mean i have a vacum leak, if so would this affect the code. any help would be great. thanks.

also could one of the other 2 iacv make it throw this code. i looked threw the list of codes and didn't see it list any codes for the other 2 iacv.

 

sounds like to me the safc has improper dec settings.. that will do it.

whats your dec setting

ps

safc is not ****ty lol.... setting it up incorrectly can stop your car from running .

you vac should sit at about 20

and Aicv look exactly the same, but they have different colors the newer Aicv are like purple and the older ones are brown.

 

yeah because i have set and reset the dec settings trying it by the book and how somebody posted on how to set it up, neither changed the way it ran.

if the vacum is at 25-30 (i need to check to be sure) does that mean there is a vacum leak?

There is 3 items that consist of the iacv if one goes bad does it throw the same code? could i be looking at the wrong one?

 

im honestly not familiar with OBDII cars when it comes to the Aicv system and the temperamental ecu. hopefully some other s14 doods will chime in.. i have not had a cel on my car ever.

as far as the vac.. yes check your lines and take some starting fluid and spray it around the base of your intake manifold.. if the revs raise, you have a broken gasket somewhere.. they are easy to change out and cost about 10 bucks. comes with the gasket to the block and the gasket that goes in between the runners and plenum.

can you tell me what you In and out setting is... that screwed me up for a bit as far as idling.

 

2in 6out and i have a n62. i know the out should be 5 but it wouldn't run at 5 when the guy tuned it? so i dont know. i have seen other people run 6 out.

just thinking out loud about that but do you think a major vacum leak would cause the car not to idle when set at 5 but would kinda look past the vacum leak if set on 6? just a thought.

 

yes sir... a leak disrupts your overall pressure.. do that starter fluid test.. and or goolge.. DIY leak detector.. you can make it from parts at home depot and use a bike air pump..

 

ok i will have to do that. but i still need to find out if anybody knows if a vacum leak will make that iacv-aac sensor throw a code.

this is what i think and tell me if this sounds right or not. but the iacv moves air from in front of the throttle body to inside the intake mani. to regulate at sertain situations dec. warm up, when the ac is on ect. so if there is a leak inside the intake mani. it wouldn't be able to adjust properly? just a thought.