Crankshaft sensor

[chrisash86]

Evening my cav won't start , it will turn over but won't spark, I've been told it's probably the crankshaft sensor does anyone have a pic of where it's located ?

[colin1]

It's at the front of the block, concealed from above by the exhaust manifold, you can follow the wiring back up the loom to the plug.

Is there an EM light/code to be read off or was crank sensor just a shot in the dark?

[chrisash86]

I recently bought the car and contacted the previous owner as he had the same problem . Found a sensor at be bottom left hand of the engine block am quite near the floor cleaned that but no change

[colin1]

If the crank sensor has failed you should have an EM light
That in turn means that there is a code to be read off

What was the physical condition of the sensor?

[colin1]

Does your car have an immobiliser fitted?
These can become quite annoying as they get older

When you say 'won't spark' do you mean there's no spark or the engine just won't fire up. Check for fuel delivery, that might point elsewhere other than the crank sensor.

[chrisash86]

How do I check for fuel delivery?

[colin1]

Remove the fuel feed onto the rail (left hand side as you look in) and crank the engine into a rag

[chrisash86]

It's definitely the crankshaft sensor I'm waiting on a new one but it won't start again! Is there anyway of bypassing the sensor to get it started?

[colin1]

I once tricked a windscreen water reservoir level sensor into thinking it was OK by removing the (duff) sensor itself and shorting the pins in the loom. Absolutely no idea if that will work with something more sophisticated like a crank sensor.
Probably not.

[chrisash86]

Been to it today wouldn't start , recovery came out checked the ht leads battery all fine turned it over and as it been started repeatedly the battery was a little flat so it he put a booster pack on . Then it started first time and since has started fine too! I hope it's the crank shaft sensor!

[colin1]

...I hope it's the crank shaft sensor!

You don't really need to hope
Has the EM light remained on with the engine now starting?

If it has, read the code off

[chrisash86]

Eml has never come on at all

[colin1]

There are either no sensor issues (anywhere, not just with your crank sensor) or the EM light bulb is blown/missing

What do you mean by 'never come on at all'?
Does the EM light come on with the ignition and then disappear after the engine is started?

[chrisash86]

Yes sorry the eml comes on when the ignition is on haven't done the paper clip test yet as the previous owner had the same problem and identified it as the sensor

[colin1]

OK
but if the EM light then goes out with the engine started, I don't see how anything can point to the crank sensor; if you've got an EM light that is behaving normally, you don't have any reason to run a paperclip test but if for some reason you decide to anyway and it's throwing up the code for a crank sensor then something quite odd is going on with your car.

[chrisash86]

It's the car off lowrider Dave and he had it the same problem, it's listed under v6 refusing to fire .