Toyota Repair: 89 toyota pickup jumper cables reversed, throttle position sensor, jumper cables

Question
I tried to jump off my 89 toyota pickup and reversed the jumper cables. I replaced the 80Amp ALT. fuse and am able to start the truck but it will not idle. as long as i hold the gas pedal down a little it will run. it has a 22r in it if any one can help it will be greatly appreciated

Answer
A question I still have is do you have a service engine light on now? If so, you may have shorted out a throttle position sensor (or Engine speed control)sensor. If you do not have a service engine light, I have to admit that Id expect to see one soon. The fact that your throttle has to be open ever so slighly is sending a message that it is idling up. If you know how to turn the idle up, you may try that as a low cost test. I would like to know if this resolves it.