I removed the 350TPI from my 88 GTA. Without thinking i also removed the ECM and complete wireharness that went to under the hood. I unplugged it from the digital dash plug located under the dashboard on the passenger side. It was sold with the ecm harness and appeared to be all one unit. Now i am installing a non TPI engine and am trying to figure out how to make the digital dash work again. Where can i purchase a diagram or harness to work the gauges and will I need a ECM??? Any info much appreciated as i cant proceed at this point....
thanks

 

A friend of mine went through this same situation. I remember him telling me how he had a hard time getting his to work correctly at first. His problem was one of the grounds. I think he said there are 4 grounds, but at first he thought there were only three. It seems the 4th ground is a wire that goes to the computer from the cluster, and the computer actually grounds that wire. He hooked it to the body under the dash and everything worked fine after that. He said the hard part was determining that there was another ground in the first place. Once he determined the situation he was able to solve the problem. If you want his advice on what to do he posts on poorformance.net as Toefur. I'm sure he won't mind telling you what he had to do.