Opel Corsa timing belt replacement

the cam turns at 1/2 distance. It take 2 full turns of motor to return cam to the timing marks. have you changed timing belts, they do stretch.

What exactly does this 'light' look like? Any light, especially if it is Yellow or red, needs to be investigated as soon as you can. The shape and colour of the light give a clue as to what the problem could be. Code $7E8 is a 'Sub menu' code on the scanner you used. When this appears scroll down to it then select it. This should bring up another code usually starting with a P then four numbers. Comment below with that code and I'll try to help you more.

If you set the engine to Top Dead Centre before you started it shouldn't be out of position or at least not by much.
You will need two M6 bolts.
The crank pulley has a notch on the edge that will line up with a marker on the engine block at the 12 o'clock position.
When the camshaft lines up there will be a bolt hole for an M6 bolt to lock the cam in position. It will be roughly at the seven o'clock position.
The injector pump lines up using the same method as the Camshaft. The bolt will fit at roughly the 4 o'clock position.
I have included an image as a rough guide.

Do you mean valve timing or are you past that and need to do your ignition timing? What year Opel? Did you line up your timing marks when replacing the timing chain? I am including a link to a video that may be applicable.

Probably a chain, but yes. It has to have something in there to keep the crank shaft and cam shaft in sync.

if the car keeps jumping 2 or 3 teeth on the timing, it's possible that you need a new timing chain/belt and tensioner.

run fault codes and check for crank/ cam position sensor fault as if they are faulty there will be no spark until the cpu knows where the piston position is.

Use the timing marks on the damper for the crank and bring it to 0 on the cam there are marks that correspond with a mark on the head. Look on autozone dot com and put in the year make and model then look at the free repair guides.

No idea offhand to be honest i would need my head under the bonnet to know what wrong .could be anything from the gauze filter in the fuel tank on the bottom of the fuel pump becoming chocked up and leaving the car allows it to drop away to a faulty pump overheating or the contacts ,maybe even a ignition module overheating ,Best advice is ask a local mechanic to have a look for you as normally these early opel corsas with the 4 cylinder engine are bullet proof they are even valve free if the timing belt snaps .

Just mark the cam and crank shaft in the position that it is in before you take the timing belt out