CE4me :

You likely have an injection system issue, but first, do check all vacuum hoses. One really hard to find and unusual vacuum leak is a bad check valve in the brake booster. If usign the brakes seems to cause more stumble, check there. Possibilities: Decel/cutoff microswitch not made or failing, 1 funky injector or leaking injector seal. More challenging problems: the hard to fix parts of the fuel injection system. Put the old diagnostics stuff on it and start checking.