Any codes?Have you tried cleaning the idle air control valve?Or looking for vacuum leaks?

No codes. Cleaned iac valve & throttle valve. Checked for vacuum leaks w/ soapy water.

You can't look for vacuum leaks with soapy water because vacuum is the absence of pressure and wont blow bubbles.The way i check for leaks is with some carb spray spraying it around at idle and watch for a rise in or fall in rpms stumbling or dying.

there are so many things that could cause a surge. if you have no codes and no vacum leaks i would have to suggest that you take it to a shop for diagnosis.you don't want to waste any money on uneeded parts.there are dozens of things that could cause your issue.

One last thing-can you tell me how many vacuum hoses there are, and where exactly they're located (it's a 2.2 litre manual). Maybe I missed one.

Thanks

no i can not pull up vacum diagrams.