Tough One! HELP!

My buddy at school has a 97 'Lude and we are having some problems. We took a look at the mechanical stuff, and the compression, CLD, valve lash, timing, cams, valves, and springs are good. We looked at the ignition side of it and thats all good. We disconnected the injectors individually. When we diconnected number one the engine has no problem running. This kinda prooved our guess about it running on three cylinders. It has a vacuum of 11.5 "Hg. Runs like shit on a vacuum leak, but dies if you kill the leak. The only codes we could pull from it were mis-fire in #1 and #2 and TPS voltage too low. We cleared those and the only one that came back was the TPS voltage too low. It was reading 9.8 percent throttle. What the hell is this all about???:angryfire

Check all sensors and make sure they are working properly. I wouldn't be able to tell you which one specifically, I don't have a lude, but if you guys checked all those things and it's working fine, it might be a sensor malfunctioning.