2000 integra i need help!

im trying to help my buddy get his car running but im not to keen on honda so i need some help.the car was just painted and a engine was built for it,also it has a conversion to bring it back to obd1(not sure why) but it would not start,so i checked timimng and i made sure the distributor was pointing at number one when i pulled a plug to check for spark i noticed that it was weak so i started looking at grounds.none of the had good contact so i fixed that problem and moved on to check the injectors.i did not have any power,so i started traceing power and i found out where all the multi color wires went to a plug then to the computer but i could not follow where all the yellow wires went.there are all kind of things unpluged so im not sure where there supose to go? also are the yellow
wires the ground or are the multi color wires the ground?also the computer is out of a 94 del sol.so is the computer blown up, or just the wrong style of computer, or is it the fact i cant find the plug for the yellow wires if u can help it would keep me from going crazy thanks