im at wits end with this issue with my 740 and have currently given up due to the intermittent nature of the issue at hand:

the following will occur at random,
before i swapped out the AMM with a known good unit i would get stalling issues that the vehicle would not start back up for a good 10 mins but would put a few times. furthermore before it stalled it would be like a no power situation where it is in gear but absolutely no power. i could keep it running but eventually it would die out. if i placed it in neutral i could rev engine. rpms were normal before the stallout(my biggest head scratcher there)

upon swapping the AMM out after i was coming home (had a guy behind me delivering a tv for me that did not fit in the volvo) after flooring it for a few miles(running but very low power and sputtering like crazy) the stalling issue was remedied or so i thought.

the other day it took me nearly a full battery until it finally cranked over and fired up. the fuel injection relay as well as the fuse are a-ok as well as the plugs, cap and rotor were replaced with a junkyard unit that was a brand new distributor assembly i lucked out in finding. wires are brand new as of late last year. AMM replaced with good used part but the rpms do stay at around 1k when in park first starting the vehicle. i checked the valve for stickyness and cleaned it before installing it.

the vehicle otherwise currently runs fine with the issue of a quick sputter on the road while driving. it will be fine than "hiccup" a few times and return to normal. no more stalling as of now.

is this a fuel filter issue? i am all out of ideas and even pro. volvo mechanics cannot figure it out. fuel pump intank is original to the best of my knowledge and the main is a used one but the donor car had 200k on it so both pumps its safe to say have well over 300k on them.

any suggestions would be greatly accepted at this time as i mentioned above im completely in the dark with this one.

one thing i should mention is that when cars running fine and id turn headlights on or off quickly it will studder but all electricals seem clear of gremlins for now no dimming lights etc.