Code 12 No start Help

[19cutlasssupreme89]

I just finished swapping in a new motor ( from a junkyard ) into my 1989 cutlass supreme, i thought i hooked everything up but the engine just cranks and cranks with no start and no spark. the computer is throwing code 12 which is a diagnostic code that means the ecm is not getting the reference signal so it will not start. any ideas on what this could be, I really need to get this car running so i can sell it before I leave the state. If anyone is in the phoenix area and can help I will pay if I can get this car running, any help is appreciated, thanks, jeremy

[SappySE107]

Code 12 means everything is ok. Its what will flash 3 times first, and then it will flash any real codes 3 times each, and then it will flash 12 3 times again for the end of the list. If it only flashes 12, then it doesn't know of any faults. Check your grounds and fuses.

[19cutlasssupreme89]

According to my factory service manual, code 12 will only flash if the ecm is not getting a reference signal meaning a ground or wire in not connected or a sensor is bad, i believe everythingis hooked up, any ideas onto which ground are bad and the locations of them so i can check them all, thanks,

[SappySE107]

They all flash 12 or they aren't working at all.

Check the grounds near the starter going to the bellhousing, and any grounds on other parts of the engine/bellhousing. Check your ground wire on the battery as well. Might need to clean the threads on the bolts.

Check the fuse panel for any blown fuses. No spark means your crank position sensor is bad, or your wiring, or the DIS module.