I got the new ECU in and discovered the old one wasn’t bad. As I plugged in the new ECU, I had the same issue … the fuel pump wasn’t kicking on when I turned the key to the on position. My heart about fell out on the floor. Like I said before, this is R&R wrenching and I do not like it. I then started playing with the wires on the ECU. Low and behold … the pump kicked on. Holy smokes. The problem was not with the ECU, but with the fuel pump relay wire coming from the ECU not making connection at the pin. I then pulled out the pin from the connector, played with it a little bit (read: used a pair of pliers on it to make it have a little better contact), re-pinned it in the connector, and have been rewarded with a consistently working fuel pump since then. Engine still isn’t starting, but the fuel pump runs! Yay, small victories! Even if your victories come after setbacks … argh.
I’ve decided to go back to the drawing board a little bit. I’ve found a couple of charts on RS25.com which will probably help. I’ve seen these charts before, but haven’t given them much mind until now. Yes, folks, I can be dense (enter: not seeing the forest for the trees cliche here). Here are the two charts I’m talking about:
What these two charts show is each of the important connections at the ECU and what their values should be with the ignition/engine in the off, on, and running positions. The plan for today is to go through each connection at the ECU with the key in the off and on positions, then back-probe the ECU to get each of the values from the pin. I’m hoping in doing so I’ll be able to figure out if something is not reading. It will be an arduous task, but I think it will provide results which may help me figure out why the engine isn’t starting.