Check your air filter to see if there is a rat nest in it. Rats love to
make their nests Mitsubishi air filters.

Most likely to be a fuel or timing problem. Open the gas tank filler cap:
does the problem still occur?

If not, could be
- a blocked fuel filter (on the firewall). You could open the filler cap,
undo the fuel line on the injector rail and blow some compressed air down
the line. This sometimes clears a clogged filter.
- faulty fuel return or evaporative purge line.
- fuel pump or in-tank filter is clogged.

Check the cam belt timing. If the belt slipped a couple of teeth the engine
will still start but have no power. Will it rev OK in neutral?