I need some ideas on what else could be causing a ruff idle on my 1980 240? I have replaced the intake manifold and throttle body gaskets, torn rubber intake bellows and brittle cracked injector seals as all these were contributing to a massive vacum leak. Also replaced plugs, cap, rotor and air filter. Before these repairs it would idle for a minute or two, shake severely then die. The way I would prevent this and keep it from dying was to disconect the oxygen sensor lead and ground it to the firewall and set the idle very high. This sounds crazy but when I hooked up the oxy sensor it would shake vilolently and die. Oxy sensor was installed new about a year ago. After replacing these gaskets and seal it will now idle with the oxy sensor hooked up and does not die. Big improvement but still idles somewhat ruff. Any ideas that may help me out?

Thanks,
Dale