Peugot 309 19 years - wont start

remove the oil filler cap and check for valve movement when turning the engine over
( broken timing belt or chain)

whistling sounds and the high rpms to a stall situation could be a loose /broken vacuum pipe possible to the transmission actuator ( automatic)
happening after a bump could be from broken engine mounts , loose ground points, harness connections loose loose battery terminals

When this happens have a can of spray starting fluid on hand, spray it into the engine air intake, if the engine starts you may have a failing electric fuel pump

sounds like a vacume leak this can stop cold engine from starting. vacuum leaks can be hard to find, it could be just about anywhere. when you have engine running spray the easy start or carb cleaner around the vacume lines, note any engine sound changes. and that will be where the problem could be, say could as it could have more than one leak.

Define - It attempts to turn over but won't catch and run ???? When you turn the key to start does the starter engage an spin the engine ? This would be a crank no start condition . If the starter doesn't engage an spin the engine this would be a no crank no start condition . Sorry to ask but i have only been an auto tech for thirty years an have heard a lot of different discriptions for these simple actions . crank no start or no crank no start . Very different diagnostic procedures . So when you turn the key to start , does the starter engage an spin the engine ,but won't start an run ?

Check the starter it could a bad cross over or the teeth on the catch wheel (or what ever it is called) could be broken and by attempting to start it you are bypassing the broken teeth and it will catch allowing the vehicle to start. Also just to be thorough double check the electrical from the batt to the alt, ignition switch and the starter.

your car need a service including oil change and oil filter change. please use a minimum of 10w40 synthetic quality oil and not the cheap mineral oil.

No further actions requested

Check the battery, it sounds like it's flat. Try charging the battery to see if it recovers, but if the battery is about 3 years old or more it is likely to have failed and replacement is the only viable solution.

change the battery but first check the dynamo and car starter