Quick question about base timing

[absolum]

I did set my timing according to the FSM , warmed it up , shut the car off , unplug the TPS and adjust the idle.I used my timing light to set the timing at 15 degree, 2nd from the right. After shutting down the car and re-plugging the TPS back in, I checked the timing again (with the TPS plugged in this time) and it's set at 10 degree.

I gone through the whole setup again and same result.When I set my timing without unplugging the TPS at 15 degree, shut the car and then after unplug the TPS, I get 18 degree.

Is it normal to have a variation in the timing reading from either a unplug TPS or a plugged TPS.

Is that normal? if not, what could be the problem?

[CotBU]

After you unplug the tps rev to or above 3k rpmAfter you set the timing rev to or above 3k rpmset timing using an extension wire for the spark plug to coilpack or signal wire on coilpack harness. not the loop!

Do not set timing or adjust idle with tps plugged in, if your TPS and ecu function correctly. The ecu will still be in controll of those functions