We have a 91 Honda Civic in which we dropped a jdm vtec engine and ECU in it. You know, the kind of conversion many have done before. But, now we are stuck with the following problem: when we start the engine, it will hunt between 1K and 2K rpm. Incidentally, the tach only works if you turn the headlight off. On the top of that, we can take the key off the car and it will not shutdown. So, where should I start checking the electrical on this car? We have spend a day testing every wire that goes from and to the ECU and were able to account for each one of them. We have also tested the ECU in another similarly converted car. It worked fine.
Now, I learned this weekend that my friend -- the car owner -- had to cut some of the wires that lead to the bumper/headlight for one reason or another. But he supposedly has soldered them back. However, at this point I wonder if that could have caused the situation and how. If you have not noticed, I am shooting in all directions right now.