hey everyone. ive got a 99 5sfe celica. as many of you know this means i have a non adjustable distributer. ive been told the computer adjusts the timing.
so my questions are: how does the computer adjust the timing? what sensors does it use to read the timing? does anyone know how the sensor or ecu does what it does in the area of timing? my goal is to "trick" the computer into advancing my timing a bit for better highway mileage and maybe some more power. surely there has to be a way to do it. ive heard i could do it with the timing belt, but then i heard i couldnt. any input greatly appreciated. thanks

can you fit a distributor from an older model?

it should work exactly the same, you should have 10deg of base advance at idle (at operating temp) and the computer keeps adding advance according to its maps until knock is detected, then it will back off, if knock happens alot, it will start to remember until the next time you reset the ecu. unfortunately the only thing you can do is make sure you're running the correct octane fuel, and reset your ecu

put a pot inline with the AIT

ok so after some thinking and research i realized it cant be done with the belt. that's for valves not spark. ive been told that i cant put on the older distributor (is this wrong?) usually putting the pot on the ait increases advance but also increases fuel. i can also try putting a pot on the MAP and the coolant temp sensor. ill probably do all three so i can play with it as much as i can. there is a device for o2 sensors called the EFIE which helps you control fuel and is recommended alot. i think with all of this working in conjunction after alot of trial and error (and maybe some 93 octane) i may start getting somewhere. any thoughts? has anyone done any of this on there celica?

What exactly are you trying to do here? You're going to upset the operation of the engine doing that, for whatever gains you make in one area of the rev range/throttle position, you're going to make everything else worse

actually i read that if you try to put too much resistance on one sensor the ecu will get mad but i figure just a little split up between 3 will go unnoticed. im trying to go for gas milage. ill try one thing at a time and see what happens. a have the torque app for my phone so i can see engine data in real time. if anything goes wrong ill know i just wanted to see if anyone knows something i dont. like how the timing is actually adjusted. is it an electromechanical linkage?