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Discussion Starter · #1 ·
Hello folks! First time posting here, hoping to gain some knowledge.

Me: Rarely ever hire a mechanic, well equipped to do all repairs at my house. (almost) lol

The Issue:
I was given this 2000 Tundra from a brother in law, who burned up the engine by overheating it to the point it locked up. The truck has 277,000 miles on it and is en excellent condition and has been meticulously maintained up until the calamity. I bought a salvaged engine with 60,000 miles and swapped it with the original engine. I verified the vin code to be compatible and intended to use the original ECM. Everything went well, except for the alarm having locked out the ignition system until I found and unplugged the wiring harness from the control unit for the alarm. It immediately cranked and ran OK. The issue remaining is what seems like a very common issue of high idle (1800 to 2000rpm), lack of throttle response until nearly full throttle ( the throttle body is in limp mode so to speak), there is of coarse an engine light constantly, but no code according to my cheap almost useless OBD scanner and so on.

Please forgive my lack of proper terminology, but I've tested the throttle body components the rheostat that the cable attaches to, as well as the motor control side. According to some intensive researching online, everything checks out with specs. in tolerance on the output of the rheostat outputs, but i never did get the other side figured out where the motor control harnesses are. I do have the original throttle body which wasn't messed up and have swapped it to get the same exact effects. I used MAP gas to check for vacuum leaks and there were none. I'm down to trying to figure out whether there is a method of me making the ECM recognize and relearn to control the engine, or taking to my local dealer for a bon-a-fide plug in and have a look in the electronics to see whats not adding up. For some reason it seems to be unresponsive with a lack of control to the throttle body from what I can best gather. I've been over the entire engine wiring harness assuring all the plugs are plugged, no pins are backed out and so on; especially at the computer in the dash behind the glove box. I used the harness with the newer engine since it was in better shape than the original, some of the older plugs were broken on the original.

One sign of life I do see from the electronic fuel/air control is when I unplug the mass airlflow sensor as it idles at about 1900 RPM it will stumble and die like every other vehicle I have in the driveway. Also, when I disconnect vacuum lines ( to the brake booster for example) to increase airflow into the intake it slows down which seems normal.

Anyway, thanks for taking the time and exercising the patience to sift through my explanation. Since I work offshore 7 days at a time and I just arrived at work for the week, I don't have the VIN number. I suppose I can phone home and get it if it might help. I'm not used to asking for help, but here I am! LOL Thanks in advance y'all!
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