Starts sometimes

[sittingduck]

HI ALL
Got a great one here for you. Have a Merit 1.2 which starts when it wants to. I can start it about one time in five tries. When it starts it fires straight away and runs perfectly never missing a beat. When it doesn't start I can turn it over from a full battery to flat and it will not fire or catch once. (no spark at plug at all). I can lock the car leave it for an hour and sometimes it will start and sometimes not I usually have more succsess when the engine is warm but not always I guess its an electrical fault probably with the imobiliser but this one has me stumped any ideas or suggestions would be gratefully recieved

[Octane2097]

sounds like a faulty sensor,
if its a 1.0i or 1.2 16v get it on a diagnostic, if its any other. try the paperclip test should tell you if you have a faulty sensor
but does sound like a faulty crank sensor (very common especialy on smaller engined corsa's)

[bluecorsab]

what year is the car, if its the early one i.e n reg 1.2 merit it will be a 8 valve with a distributor, no crank sensor, single point injection, later ones are coilpack so has crank sensor and is multipoint injection

[sittingduck]

Thanks for the Quick replies
The car is a 1.2 P reg Merit First registered in May 1997
I will replace the crankshaft sensor and let you know how it goes

[sittingduck]

Finally got round to replacing the crankshaft sensor (weather has been bad here no place inside to work on car).
You guys were spot on. It was easy to change (once I got the right part) and started straight away. Hasn't missed
a beat since and all for £27 Bargain Thanks for the advice