Hi all, first post to this forum. Thought I might share the following for whatever its worth.
I've owned and operated/maintained Volvos since the mid seventies. I've never been "stumped" with a problem (well, not for too long, anyway...) on any of them. I've owned a 445, a 544, a half dozen 122s, k-jet, 2.2, 2.4 - you get the picture...
Until recently, I would have said that I love them all. I can no longer say that because back in November, I succomed to a minty '91 Rex/Regina 745. It is an exceedingly well kept 120k dealer maintained car that idled like crap. It's crappy idle would show it's ugly face both in and out of gear.
I'm no stranger to stage zeroing a car - it was done and done right. Compression is 160s on all four. Leakdown is 10%ish on all four as well. Fuel pressure 43lbs WOT, 36 at idle. (800 ft. above sea level here). You can see your reflection inside the throttle body. Rex and Regina both pinned out within spec.
Admittedly, I haven't purchased a new VDO IAC valve. At the same time, I have tried three different (cleaned) used ones. No joy, until this afternoon.
I installed a nasty old "wo out" 2.4 Bosch IAC valve (2 pin) just for yucks and the car idled like a NA Volvo should idle - maybe for the first time in many years - who knows. I drove the car for 35 miles with no codes (apart from the what should have been factory installed 3-2-1) surfacing.
Go figure. Who's to say, maybe a new VDO IAC would give the same results, but something in me doubts it. I've never "futzed" with a Volvo more in my life... the thing just ain't a Volvo, in this respect.
Forgive the preachin' - hope someone takes something from this.
I've owned and operated/maintained Volvos since the mid seventies. I've never been "stumped" with a problem (well, not for too long, anyway...) on any of them. I've owned a 445, a 544, a half dozen 122s, k-jet, 2.2, 2.4 - you get the picture...
Until recently, I would have said that I love them all. I can no longer say that because back in November, I succomed to a minty '91 Rex/Regina 745. It is an exceedingly well kept 120k dealer maintained car that idled like crap. It's crappy idle would show it's ugly face both in and out of gear.
I'm no stranger to stage zeroing a car - it was done and done right. Compression is 160s on all four. Leakdown is 10%ish on all four as well. Fuel pressure 43lbs WOT, 36 at idle. (800 ft. above sea level here). You can see your reflection inside the throttle body. Rex and Regina both pinned out within spec.
Admittedly, I haven't purchased a new VDO IAC valve. At the same time, I have tried three different (cleaned) used ones. No joy, until this afternoon.
I installed a nasty old "wo out" 2.4 Bosch IAC valve (2 pin) just for yucks and the car idled like a NA Volvo should idle - maybe for the first time in many years - who knows. I drove the car for 35 miles with no codes (apart from the what should have been factory installed 3-2-1) surfacing.
Go figure. Who's to say, maybe a new VDO IAC would give the same results, but something in me doubts it. I've never "futzed" with a Volvo more in my life... the thing just ain't a Volvo, in this respect.
Forgive the preachin' - hope someone takes something from this.
I learned very quickly that if you're easily butthurt, turbobricks isn't the forum for you. That being said, no "just kidding" needed. It honestly took me like a month to figure out how to post pictures. All you need to do is upload them to 
