I checked all the vacuum hoses, thoroughly cleaned the MAF (it *was* filthy), and passed a lot of messages to my dad who works with a Volvo mechanic several states away.
He ended up saying "Probably the ETM"
So I took it to a local foreign car place here, and they said "Probably the ETM" - 800 for parts and 250 for labor to replace.
IF it's the ETM, I'd like to do it myself, and in the cheapest possible manner. But searching here a bit, I see similar symptoms in threads about MAF (maybe cleaning wasn't enough), TPS, and others.
So I'd like to get the opinion of folks here, both on diagnosis and best path forward.
General symptoms -
Idle hunts between about 800 to 1200, car shuts off at idle about 40 to 60% of the time.
If I drive it gently, I can get around fine except the problem with stopping and idling, but if I try to run out the gears at all, something isn't right at high RPM - it doesn't feel very happy to be up there, like there are fuel issues. I could see this being super-rich running, but can't say for sure.
I had no codes at first, but I now have P1103 and P1620.
One weird thing - the first thing I noticed was that the vacuum line to the inlet air thermostat was unhooked. I plugged it in and *thought* I'd fixed the problem, drove the car around for about 20 min and everything was fine. That's the only time in the past 2 weeks that anything I've done has seemed to help, and I guess it must have been a coincidence.
I'd love the opinion of folks here.
IF ETM is the consensus -
Is used an option? I know it will fail again, but for the difference in cost (and due to some changes I expect in the next year) even if I have to do it again later, I'd much rather spend $175 for the part and solve the problem for the short term then come up with $1000 right now.
If used isn't an option, what is the cheapest option?
Thanks in advance!






