84 Spark Problem - looking for used ECM

[riley]

We have an 84 T-Type that is not getting any spark. We've check the cranksensor and it's getting juice but the injectors are not. The coil is getting power but not firing. Would this be an ECM problem or something else? There are no trouble codes given via the SES light. It blinks for code 12 but no other codes. What is a good source for finding a used 84/85 ECM aside from eBay?

 

[conn84gn]

I have a good used one

 

[cool 84]

We have an 84 T-Type that is not getting any spark. We've check the cranksensor and it's getting juice but the injectors are not. The coil is getting power but not firing. Would this be an ECM problem or something else? There are no trouble codes given via the SES light. It blinks for code 12 but no other codes. What is a good source for finding a used 84/85 ECM aside from eBay?

Cam sensor.

With the key on, the injectors should have positive but no ground. The computer fires them by providing a ground. Most likely it's cam or crank sensor.

 

[riley]

We just replaced the crank sensor. We'll check the cam sensor next. If it is bad is there a difference between cam sensors on the 84/85 and the ones on the 86/87? DirectScan won't work with the 84/85 ECMs right?

 

[racemybuick]

as far as I am concerned, the cam sensors are interchangable....If I am wrong, PLEASE someone let me know!!!! As far as direct scan, no it will not work with the 84-85 ECM... I have upgraded the ECM to the 87 unit and will run the direct scan as soon as the motor is done!

Good luck!

John :biggrin:

 

[SLOW_85]

Go here:
http://www.vortexbuicks-etc.com/

Link on the left, troubleshooting. Should be some useful info there.
HTH :biggrin:

 

[boosted84]

If your going to change the computers you might as well upgrade to the 86/87 and put a scan tool on it to monitor knock and to tune