i have an 89 irocz i bought it from a guy who had no clue what had been done to it. any ways the engine has supposibly been replaced and whoever did it was retarded as far as wiring. i bought it not running my brother-in-law and i got it running but now it doesnt want to idle. it is a 305 tpi. i used a paper clip and only get code 12. any ideas? check engine light never goes off. i have already replace thermostat and radiator because it was over heating.

 

code 12 is flashed first before any other codes to let you know it is working, code 12 is not a malfunction code

 

Code 12 is always there. It's not indicative of any problems- it just shows the system is working. But, if the wiring was done really poorly, that'd be the first thing I'd check into.

Edit: ninja'd :/

 

Actually code 12 does stand for something. It's telling you the ECM isn't receiving a signal from the distributor. But that's because the engine isn't running. Code 12 is normal.

 

I'm having the same problem with my 91 w/ the 305 tpi. I have to give it gas for it to idle until it warms up then it runs just fine. I think the problem is the ECU is stuck in closed loop... or open... whichever is the one where the car starts running off the O2 sensors and idles itself. I was told that a few ignition cycles should relearn the idle but that never fixed it. I still have the same prob and Im about to give up and buy a scan tool to relearn the idle lol