My 2001 civic intermittently stops accelerating and then kicks back into
gear while driving. It's not a stall, because the car doesn't completely
lose power (the radio, a/c, etc. keep working), but the car stops moving.
It almost feels like trying to drive with something stuck under the wheels
-- I press on the accelerator pedal but the car doesn't move. No
indicator lights appear, nor are any problems coming up in computer
diagnostics. The service people thought the problem was in the fuel
supply and have tried a couple of things, including replacing the fuel
pump, but there has been no change. They've basically admitted that they
have no idea what the problem is, but the car isn't safe to drive. It
only has 49,000 miles on it.

Does anyone have any ideas at all?