This saga has been going on for a month now. 93, 240 not running right.
Things done so far,
IAC valve cleaned,
Last Code read, 232
Flame trap clean
Run thru diagnostic test, with no conclusive results.
Cleaned inlet throttle body
Cleaned all ground connections
Cleaned all sensor connections
Mass meter checks out,
O2 sensor seems to work though voltage levels I can't benchmark against.

Symptons, presently, low power, surges some what when accelerating hard. Idle wonders some but is more stable than previously. Cleaning IAC valve helped.
I am suspecting the knock sensor presently.
I put the timing light on last night and ran the the RPM up some. I could see the timing retard and advance at a steady RPM of approx 2000. Would shift maybe 5-6 degrees than shift nack intermittantly.
Toady I am beating my head with a brick.

Have you checked for vacuum leaks? The main intake hose loves to get worn through.

You can yank the LH fuse (#6?? in your '93) to clear the memory to see if it comes back.

Are you *sure* the AMM is good? There's no real bench test for these things.

Check the ignition system for codes.

-Ryan
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Athens, Ohio
1990 245 DL 130k M47, E-codes
1991 745 GL 280k (Girlfriend-mobile)
Buckeye Volvo Club

Not sure, but a couple of months ago I kept getting the 2,3,2 code in my 1990 240. I tried all the same things and also a new AMM and fuel pressure regulator, but kept getting the 2,3,2 along with sluggish performance and some surging, stalling. I finally swapped my ECU (561) with an upgraded one (951) and that solved the problem. No more 2,3,2 and the old 240 runs like a champ. Not sure if the 93 had the "561" ECU, but if so you may consider upgrading. I picked up a reburbished one on Ebay for $45. Good Luck.