i tried tapping it but to no avail. i think the diafraghm(i killed that 1) might be ripped in the egr valve. how do i test it with a vacuum pump?

87 4runner 33" bfg mt's no lift. dubbed the marine by my frinds. dead as of august 14 2005. 84 ex cab p/u 33"a/t, 3" suspension+3"bodylift, thorley header and 2.25xhaust, downey midrange cam+rocker set, very milled head! NO RUST!