Banned for not
following the site
Join Date: Feb 2008
Location: United Kingdom
If it refusses to turn over then it is most likely corroded terminals on the 2 relays under the cover in front of the battery. Normally comes up with a CODE light on the dash too if this is the case.
If it turns over and wont fire, then the rank knock sensor is probably the culprit, look down the back of the engine for a brown plug, ensure it is connected securely and tap the sensor on the end. Try to start it again. There will be no code light, but you will have an INJECTOR light if this is the case.
The other thing that springs to mind (which I hope it's not) is the cam belts just gone, If so you'd have heard a clatter as the pistons hit the valves.
Could you also let us know which engine type and size you have, my replies are for a Twinny but I suspect you have a Boxer.