How long would it take to hyrdolock an Impreza engine by running it on 3 cylinders?

I started the engine and it ran on 3 cylinders for 30 seconds. Plug leads were checked and all was fine.

Tried to fire it up again and the starter just clicked. The engine was very hard to turn over so removed the plugs and turned over by hand and petrol came out cylinder 4.

Changed leads and plugs and fired it up, again, it run on 3 cylinders. Switched off and attempted to start again. Starter clicked again.

Removed plug 4 and turned engine over by hand, again lots of pertrol came out.

At this point Im thinking injectors is stuck open or seals have gone.

A compression test on that cylinder today came in at 100 and petrol was in the oil. Borewash.

Managed to get the compression back up to 150 on that cylinder, new plug in and lead on.

It fired right up on 4 cylinders?

Im now thinking the injector was stuck open but is now working fine?

If the plug or lead was faulty and the plug wasnt sparking, would an injector that was working fine hydrolock the engine in 30 seconds?

 

How much fuel is coming out,a teaspoon full or a cupful?

 

more than a teaspoon or less than a cupfull?

 

yes more than a teaspoon as it was enough to lock the engine but I wouldnt say it was a cupfull.

It was enough that you could see it coating the rockers covers and hear it hit the floor

 

I'd try another injector in that cylinder,sounds like its sticking open and as the rail is under constant pressure once the engine shuts off its leaking into the cylinder.