1991 Opel Vectra wont start by turning the key.

1991 Opel Vectra
Got a 1991 Opel Vectra which starts fine usually. But some days it wont start by just turning the key. Battery is new, tried hitting the start motor and also tested the electrical circuit all is fine. However when it wont start, i can put it in 2nd or 3rd gear then give it a bounce or a push. Then it starts. What could this be ?crankshaft sensor?

When you say it won’t start do you mean the engine will not turn over, click noise or nothing happens at all?

Nothing at all happens when you turn the key to “START”

Have someone hold the ignition key in the “START” position and check for battery positive voltage going to the “S” terminal on the starter. If Battery voltage is found and the starter also has a good negative ground, REPLACE THE STARTER. If no battery positive is found check the wiring in between the starter and the ignition switch. Make sure to test for voltage going to and from the neutral switch on the clutch pedal. Could be the clutch switch is faulty.