No, you don't have to take valve cover off it you can see the timing mark on the Cam gear.
No, it is the opposite, cam rotates once for each 2 turns of the crank.
It is a 4-stroke engine, so each piston needs to go up and down 2 times to complete 1 full cycle, so up-down, up-down = 4 strokes.
That's why Crank gear is 1/2 the size of Cam gear, if Cam gear had 40 teeth, crank gear would have 20, so rotating belt 40 teeth would see cam rotating 1 turn but crank 2 turns
The 4 strokes
1. intake stroke, piston is traveling down with intake valve open, pulling in fuel
2. compression stroke, piston is traveling up, intake valve is closed, this compresses(heats up) fuel so spark can ignite it
3. power stroke, spark plug ignites fuel and piston is pushed down with great force causing crank shaft to spin faster
4. exhaust stroke, piston is traveling up, exhaust valve is open, this pushes exhaust in to exhaust manifold.
1. intake stroke starts again, end of 1 full cycle
The crank only needs to be set at #1 Top Dead Center(TDC) for correct timing, it doesn't have an intake stroke or power stroke difference, piston is either at the top or the bottom that is all it does, up and down.
The Cam controls which stroke the piston is on by the opening and closing of the valves
So crank on #1 TDC, Cam mark lined up, and on the 2.3l the Oil pump/Aux gear also needs its timing mark set, this gear tells computer what stroke each cylinder is on, Cam Position sensor is here, Cam Gear and Aux gear are the same size so spin at the same rate, once timed computer "knows" cams position by "knowing" Aux gears position..
Crank position sensor tells computer when #1 is at TDC and engine won't run without that signal, Cam position sensor helps fine tune fuel injectors and spark for better MPG and performance
Last edited by RonD; 01-15-2016 at 10:01 AM.