It sounds and feels like it's misfiring on one cylinder at idle speed and up through about 3.5 RPMs. At higher RPMs the problem is undetectable. But the whole car shudders with hesitation during acceleration until higher speeds are reached.
I've changed all of the spark plugs (got fancy new iridium ones), and that didn't help the problem. But I noticed that the ignition coil tubes were covered in oil and the spark plug heads were in oil. So I changed the valve-cover gasket, but that didn't fix the problem. Also, one of the coil tubes is slightly cracked at top part that holds on a rubber gasket.
I tried to isolate the problem, but whenever I disconnected a spark plug wire the engine would just die. So it seems to be an intermittent misfire.
There is no real fuel filter on this car, the whole fuel pump assembly has to be changed, although there is a little strainer that can be replaced. I haven't tried toying with that yet. I don't think it's the fuel pump, but I have no idea.
The air filter is clean. The radiator fluid is good. Transmission is fine. Pieces of plastic are breaking all over the place, and the ceiling foam is falling apart, but otherwise it's been a great car. I can't figure out this problem.