So you kept the engine complete from the 1997 including the throttle body, injection, and intake? If so that is probably part of your problem. From what I have read the 1997 injectors are not compatible with the 2000 computer. Do you still have the the complete intake (intake, injection, and throttle body) off of your old engine? If so put it on the 97 engine. I just did this exact swap. A 1997 engine into a 2000 vehicle. All I used from the 97 was the long block. Block, head, and sheet metal(pan and covers). Everything else came off of the 2000. The whole intake system, exhaust, steering pump, a/c pump, alternator, everything came off of my 2000. The ecu's are to specific to each vehicle, year, and its systems. I hope this helps.