I tracked down a surging idle to a frozen iacv. It looks like a new oem unit is well over $100. A generic part is $31. Does anyone have experience with the generic? I learned years ago that some parts (MAF and others) need to be oem.

AND

I'm planning on replacing all the rubber vacuum lines with silicone. Has anyone seen an accurate diagram of vacuum hose routing?

1984 245 base model with M46

 

Can you unfreeze the valve? Better than the cheap one... I personally don't have any experience with that valve aftermarket but generally with electrical parts it's better to avoid.
The hose diagram is a simple one for that car, why don't just replace them one by one? Otherwise the Volvo Green Book should be consulted.

 

Hoses: not sure what's original, would like to do it back to "stock".
Tried unsticking it with solvents and lubes. No joy. Makes a "click" noise but no movement. They don't open for servicing. There are junkyard parts available, if the aftermarket piece is crap, I guess I'll get a used one and clean/lube it well.

 

When I replaced the vacuum lines on my '89 740 I just this link as a reference...

https://www.brickboard.com/FAQ/700-9...oseReplacement

and I used 3.5 mm ID hose...they make for a tight fit at that size.