So I finally decided to do this today.. Everything was going well and quick, until I got to the point of removing the clear plastic window/black plastic frame. What the hell.. I've undone 9 screws around the edge (the write up says 9/10..?!) and can't for the life of me figure out whether there's an...

ding ding ding! It appears we have a winner. Took out the IAC, sprayed it liberally with carb cleaner (didn't touch the connector, don't trust carb cleaner around those, but I might be paranoid) and replaced. Also cleaned the flame trap a bit (wasn't too bad, actually, same with the throttle body). ...

tried unplugging the IAC valve.. No real reason, just thought I'd try it. The idle went smooth right away, but very low.. seemed lower than what it should be anyway. It kept slooowly creeping down until it eventually stalled, but it took maybe a couple minutes and it was, funnily enough, pretty smoo...

correct idle speed should be 850rpm..

here's a good link for a PCV replacement "how to": http://lakesidedp.com/uploadpics/pcv/ Note that this link, as far as I can see, does NOT mention the flame trap. I don't know enough about the PCV system in the 850 really.. In the older volvos, the flame trap is a little plastic or brass ...

hm.. just ran down to the garage and tried unplugging the maf connector.. Oddly, plugging it in and out had no effect whatsoever on the car..? The car started at the 2000rpm idle for a while - unplugged the MAF, no change. After a while, it started cycling between high and low (well, this "low&...

thanks, but I HAVE checked the codes, there were none

I was talking about what they have at the dealerships, that allows them to check different values in real time (like fuel trim, as JDS60R mentioned)..

As I understand, I'd need an OBD reader to check the fuel trim, right? Will ANY OBD reader do that (like el cheapo from the local parts store) or..?

Actually, come to think of it - will any OBD reader be able to reset the service light as well (VDO instrument panel..)?

ah, thought I'd check on this thread, almost a year later.

Yup, I guess it is the ABS check up thing. I kept thinking something was wrong with my car until I drove a couple other 850's and they did exactly the same noise, always at 30km/h.

Good to know there's nothing terribly wrong with it

Hi guys, Been trying to fix this on my 850 for a while, thought it would be the engine coolant temp sensor, but alas, just replaced it and didn't change a thing :) The car idles at around 2000rpm after a cold start, slowly climbing up to 2100 or 2200rpm for 10-20 seconds, then starts alternating bet...