Incorrect Timing Can Cause Backfire.
On an interference engine you can have internal engine damage when you attempt to start it. On a noninterference engine it may not start or it may backfire, or miss, if it does start.
Engine Timing, Unburnt Fuel
Timing is off. You may need a new timing belt.
Timing is off ...
The chain can not backfire. If it is installed off time it can cause a backfire, which could conceivably damage a starter.
As with any engine, timing, and also carb problems.
Incorrect timing or plug wires connected incorrectly.
Well I really have no idea what a ldv is, but if your timing belt breaks and your engine is an interference engine there will be damage. If it is not an interference engine there will be no damage.
If the timing belt on a 1.6 Astra breaks, it can damage the engine. It is more likely to damage the engine if it is a timing chain, though. A timing chain is made of metal and a timing belt is made of a heavy duty rubber.
Timing , pure and simple. If the timing is out then your fuel / mixture will detonate when the piston is in the wrong position in the cylinder. This can lead to a backfire
You may want to have the engine timing checked?