i have a 1996 2.5l, and its running terribly. the idle is extrmemly rough (almost sounds like its going to die, but doesnt), and just runs very rough overall (loss of power). it all started when i overheated it, and blew the water pump. but since then i have replaced the water pump. after i replaced that i noticed the radiator fan was not working (probably why it overheated in the first place), so we tried hooking it up directly to the battery to see if the fan motor was bad, but it turned on so that was ok. after that i tried to start the truck up, but now it wouldnt start! the next day i tried again and it started! i did nothing exept give it time and it started... so it started to get hot (fan still not working) so i shut it off. let it cool down and see if it will start again, but this time it doesnt start. it would crank over but just wont fire up. so thoughout the day im trying to start it with no luck still... the next day i try again and it fires up... like theres something in short term memory, dont know but thats what it seems like. we were thinking it could be the relays (auto shut down relay), so i switch the a/c relay with the shut down relay (all the relays are the same), and still no start. next we got a code reader, it doesnt read any codes, but it does erase the cpu memory... so after erasing the memory, now the truck starts every time, but like i said before it is very rough, which is strange because before i reset the cpu, when it did start, it seemed to run fine, the idle was normal and sounded normal.... oh also, after i reset the cpu, now the fan is working again, so i dont know what the problem with that was. if anyone can add anything helpful, i would very much appreciate it, its been out for too long!
oh ps, i do realize that the 2.5l is not a common motor, but if anyone has any general help/info, i would be happy to hear it! thanks for any help!

 

If you got it so hot it melted the waterpump, you could have serious internal problems!!!
is there any smoke out the tailpipe???
I'd start with a compression test, then a Leak-down test and a Block test just to make sure I wasn't wasting my time on a "cooked" motor.
Good Luck

 

well it didnt actually melt it, but the bearing broke, so it was all wobbly and i could hear it scraping against itself when i gave it gas.
there is no smoke or leak of any kind that i have found...
thanks for the help!