my girlfriend recently came across a 89 civic dx. i guess it had blown a motor a few years ago, the guy replaced it or repaired it, never got it running 100% and then let it sit 3 years before i came across it. so my g/f test drove it and it ran ok for sitting for 3 years except it would die when it came to a stop. well first went and got new gas as the old gas was in there for 3 years, new cap and rotor, new a/f, some injectors that were good that a buddy had lying around were put in, and it was better, now instead of dying at a stop it will rev up and down up and down up and down at idle, from 850 - 1300 or so. when the a/c is turnd on it stops. no vacum leaks, no check engine light, and im pretty sure the TPS is good, not 100% sure tho, i did unplug the TPS and it did thrown the check engine light and it started idiling at 2000 rpms. any ideas on what the problem could be? help if possible! thanks in advace!

 

Check the IACV, and then bleed the radiator... Also, some hoses may have dry-rotted from sitting for so long... I would go ahead and replace all the vacuum ones.