I'm working on a 2000 altma gle. Someone has made a mess of this car trying to work on it. I wanted to check the timing to see if it was correct. My book tells me to disconnect the tps and then check timing. But with the tps disconnected it idles at 2000. The other thing is it says to adjust the timing with the cam position sensor. Is this the proper way to check timing or can it be check without a scan tool?