Just wanted to update everyone on this. Problem turned out to be transmission
fluid. About 30000 miles ago, I went to one of those Jiffy lube type places
and had my transmission fluid flushed. Turns out they used regular ATF instead
of some special stuff Honda uses in their cars. I took my car to the dealer
to have them replace the fluid. The shuttering went away afterwards. The
shuttering was actually the torque converter. All is well now.

Erick

On my 1998 Honda Accord 4-Cyl, my engine starts to shake/stutter when I'm
in 4th gear (automatic) usually between 1600-1900 RPM's. If I force the engine
to downshift, it goes away. I also started to smell a little gas vapor coming
from my vent right around the same time this started happening. It's faint
and I can only smell it when the car is not moving. I don't smell it with
the A/C on.

So far, I've replaced the spark plugs and wires and distributor cap and rotor.
I've also gotten the timing belt package replaced. Again, this started before
I did any of this stuff. I looked into replacing the fuel filter but the
1998 Accord has it built into the fuel pump so I don't think that's it.

Other than this annoying things, the car runs smooth. I have no idea what's
wrong. Can anyone suggest something? Thanks!

Erick