My 1988 Toyota MR2 will start but will not stay running. What would cause it to do that? The injectors are working but don't seem to be getting fuel through.

Well my first thoughts on a car as old as that is looking into vacuume lines. I had an 88 MR2 myself and one of the first things I did was vacuum lines, the stock ones were very brittle and a bad vacuume leak can cause issues such as you are describing. As far as the injectors go, how are you testing them?

I have already replaced most of the vacuum lines. I ran out of hose before I got completely finished but I will get some more. About the injectors, I took them all off and wired each to a battery and listened to it opening. I also used a syringe and some vacuum hose and forced some gas into it and then opened them and they shot the gas out. I replaced the injector seals also. It will start strong after it's been sitting for a while without me trying to start it but after it cuts off it wont start back unless I turn the key half way and back off a few times to pump some gas.