Read this thread...
https://www.fordfiesta.org/threads/fiesta-1-6-j-code-timing-problem.8918/post-24304
It can open some old wounds, but this forum needed to heal from the frustration a Ford owner had...
All the "timing" sensor figuring out, is done to the rear, the two upper cam sensors (Intake and Exhaust) with a third - the output at the Crank, is the Crankshaft Position Sensor - and it's position on the bell housing that mounts the flywheel - the clutch, or flex plate - to the transmission.
There is also a bar you apply ACROSS the output side upper cams - fixes two camshafts that once properly aligned - this tool drops into place lets you then fixate the cams so they don't move and let you put on the belt on the front.
There are two sets of cam stop tools - one to the front is the curved piece that locks the pulley gear set in proper position, but the camshafts themselves have to be set from the rear, that is a long bar that drapes across the two cams and a slot or opening in the cylinder head for it to drop into place and fixate the cams once the front pulleys are set.
This second cam stop procedure HAS to be done because once the Balancer is pulled off - the aspect (timing alignment) the bottom toothed gear had, is now gone. So the tooth to crank seat position is now off, so the cams, crank and balancer with the inner toothed sprocket gear, all need to be fixated - BEFORE you put on the belt - then once the belt is on - all parts are tightened together so the timing position for all sensors will turn correctly and the engine will start and run.
It is not enough just to do the front pulley - because the cams may still have "advance" applied to them from the idle and residual oil left in the chambers that does not drain out. Partially due to the "centrifuge effect" from the oil spinning in the advance chamber still occurs well after the engine has idled down.
In fact you can see this effect by looking at your RPM gauge while the engine runs - the idle speed of the engine fully warmed up is about 750 RPM, but if oil is still in the chambers - it affects the timing and idle speed - this is part of the engines emissions controls - the oil is still draining out of those upper cam chambers those pulley-gears cover. .So once that oil finally drains out - it may not have placed the cams in the fully reset (full retarded no advance) condition when you shut off the motor -
before it had the chance to get all the oil out of those upper chambers.