86' ECM broken?

[samsterman99]

After 6 months of owning this car I have finally cleaned up the wiring that the previous owner butchered up.
I have a CCC quadrajet, with the TPS and the Mixture control.
I have taken care of every code but #21, which is a "high TPS voltage".
I checked the refrence wire, and that was getting the 5V, and the ground is solid, but the signal wire that goes back to the ECM is giving a constant 4.75V. I unplugged the TPS and It is working properly. SO I went directly to the ECM and tested the board. The ECM is pushing out 4.75 volts through the refrence wire to the TPS. How is this possible/I assume that the ECM has just gone bad.
I found a ECM for 60 bucks, and may try that one, but at this point I hate to throw any money into a carb, when I could spend the money to go FI.
Anyone have any experience with GM computers. I am pretty sure the ECM and TPS on the 86 work just like the Fuel injection ones work.

 

[496truck]

Sounds like you did your homework and are on the right track. No reason the ECM should have voltage on that terminal. It should only be reading what comes in on that one.

TPS on a carb should work the same way as an EFI would.

 

[samsterman99]

Yeah, i have not read anywhere of a problem like this, I am going to Autozone now to order my remanufactured ecm, 59$, will be here Wednesday. I was just checking to see if maybe the circuit board was known for shorting somewhere and I could easily repair it, without having to dump more money into a ancient technology.
I will update if I come across anything else.

 

[samsterman99]

Autozone said I have to send the ECM in to get "repaired", and that takes 7-10 days. I dont really want to wait that long and pay 60$ to have someone go through my ecm and try to fix it. Anyone know where to get a complete TBI, manifold, harness and wiring kit? I want to just plug and play it, since I have the O2 sensor already for the ccc carb in there, and all the other sensors are already in place for it, I should just be able to swap sensors, ECM, and wiring harness correct?

 

[496truck]

You'll also need the fuel pump and sender for the tank.

From what I understand there are junkyards in your part of the country that have these old trucks in stock. Out here, different story. I'd try a pull your own parts type junkyard and get everything myself.