WOW I am an idiot - IAC Valve

msm15 · Post by **msm15** » 24 Nov 2008, 13:21

First the smart part - I followed Lee's advice and removed and cleaned the throttle body and IAC valve they were both filthy and needed a major cleaning - it made a huge difference on the cold morning start ups.

Now the stupid - I forgot to put the claps back on the hoses going to the IAC valve.

Result - nothing at first m but I think I hit a bump and a little while later my engine starting going crazy - first I started to loose power, then when I came to a stop it would just about stall out and the rpm's would go way down at idle, I didnt realize at first what was causing it but I looked at my boost/vacuum gauge and realized and zero throttle I had no vacuum istead of 18-20.

Dont know if I should have or not but I drove it home about 5 five blocks - from the area it all started to happen. as soon as I parked the engine died. Popped the hood and sure enough - the lower hose going into the IAC fell off.

So I reconnected it put on all the clamps, and started it up, it ran rough at first and it was kinda cool to see the ECU try to establish the correct idle RPM, it had got all messed up because it was running to lean before. eventually it stabilized and the car seemed fine.

I checked for codes as the CEL didnt come on, and it did return a P01701 or P01710 forget which one - either way saying the system was to lean. I reset it and took it for a drive and eventually the system stabilized and the code didnt come back. I did get another code though about the Idle air system malfunctioning I reset that one too but havent driven it since.

I hope in the 5 blocks I drove with it like this that it didnt do too much damage.

Japedo · Post by **Japedo** » 24 Nov 2008, 15:34

Doing stupid things and reflecting on them is the best way to learn. Well, maybe not the best way. But i bet most people have done alot worse things than that!
I doubt you damaged your engine in that little bit of distance but checking it out wouldn't hurt either. Good luck

Japedo
94 850 turbo
01 V70 XC

soundquest · Post by **soundquest** » 21 Mar 2009, 10:45

Do you know where I can find step by step instructions with pictures on how to clean the throttle body and IAC valve? Thanks.

Post by **Ozark Lee** » 21 Mar 2009, 15:07

Do you know where I can find step by step instructions with pictures on how to clean the throttle body and IAC valve?

I don't know of a writeup but it is very simple. You need to have a new throttle body gasket in hand as well as new hose clamps for the IAC lines. I just use carb cleaner on both. There is a marketed "throttle body cleaner" but I don't think is chemically any different than carb cleaner. Remove the intake hose and then the throttle body and spray and scrub.

If you decide to clean the MAF sensor while you are at it use MAF cleaner or electrical contact cleaner but just spray it on and let it dry. The MAF will be permanently damaged if it is scrubbed.

...Lee

Post by **tailor** » 21 Mar 2009, 17:19

A heads up! Do not get any carb/throttle body cleaner on the rubber hoses, it has a nasty habit of ruining them. It was a costly mistake on my part,I believe a petrol bath is more gentle, if you need to clean the varnish away.

my 0.02c