I have a problem, which can only be inside the ECU unit. The engine functions properly, except that at random intervals it will shut down. It doesn't seem to be related to engine RPM, temperature, or oil pressure.
I've been through everything else in the electrical and fuel systems and the only remaining piece is the ECU.
Does anyone have a schematic diagram of the ECU?
It doesn't appear to be very complex internally. A watchdog timer is used on the connection from the coil/tach to provide the failsafe for the fuel pump relay rather than the old version, which had a switch in the MAF.
A 6 channel analog to digital converter is used to translate the sensor signals for the 6801 microprocessor. A handful of other linear and digital IC's and discrete transistors handle the drive for the injectors.

-thanks in advance

 

Replaced the largest of the electrolytic capacitors (100Uf at 63 volts), as it appeared to have significant ESR (equivalent series resistance - leakage). That eliminated the propensity of the ECU to shut down the engine while travelling at 70 mph. Now to get rid of the tendency to stall at idle.

Only two other electrolytics in the ECU, I should replace just out of principal.

 

if your car is a 5spd i have a ecu if yours is bad just pay shipping. car is a 84

 

I have had similar random shut-down problems. New ECUs did not fix it.

 

the ecu has one main ground for everything since the ecu aint grounded itself.. the ground is located in the engine bay on the intake manifold...

 

Heres a quick test, run your car untill it shuts off on its own, once it does get in the engine bay and put ice on your ignition control module till it is cool. your car should start right back up. if this is the case replace your ignition control module. you can buy it from prostreet motorsports online. i just had to replace mine, such a PITA till i figured the problem.