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This can happen when the engine has been cranked a lot
, such as in circumstances as you have, trying to bleed the system...and it can cause the starter relay to fail - burn, causing it to stick on - so that when you just switch the key on..the starter activates , as you describe..
You will have to check that - the relay is in the engine bay fuse box.. removing it should quantify the problem and then renewal will cure that.
When bleeding these systems - you should fill the new filter with diesel prior to fitting and then crank the engine in 4 -5 secs bursts giving the same time between for the starter and relay to cool.. to avoid the above happening - so sort the relay as above and the do it all again - as above remembering to fill the fuel filter with diesel before trying to start it and then it should start and run ok after that per norm..
You might just have the same problem having occurred with the starter motor itself - but usualy its the starter motor relay as above so check that first.
I will give you an image below - to show its location ... click to open.
I Sincerely hope I have helped you - Please ask me if you need more help...
Kind Rgds, MIKE
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