So after cleaning up the engine bay today I noticed that the injectors were marked up 1-4 but not in the order but in the order of 4, 1 , 2 , 3 is this correct ?

er, isn't the firing sequence usually 1,3,4,2

 

 

 

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This is what I found with marker pen

You can't see the injectors, they are in the cylinder head.

They are coils, someone has marked them with pen. Probably when diagnosing a missfire and swapping them around.