We are working on an 89 jeep Comanche that will start and run only if you hold the gas pedal, What could the problem be? We have replaced the fuel tank due to a lot of trash in the bottom, we have replaced the fuel pump, strainer and filter as well. We have also cleaned the injectors and the fuel rail with carb cleaner. We have checked some vacuum lines to see if there was a leak in the system, and I have also tested the harness for the injectors via noid light. The fuel pump relay does work, and the cap and rotor are clean, and there is spark going to the plugs.