Having trouble starting my 1.8 liter toyota celica. Only starts by pumping accelarator. Once it starts, I have to continue pumping accelarator. Hold the idle at about 2000 rpms for a minute ir so. Then car will idle ok and runs fine until I let it sit for a few hours. Same problem all over again. Replaced idle air control valve. No such luck. Does the same thing. Car will start ok if I start within an hour. What to do?