My ford focus 2.0 litre diesel 2009 model only start when parked nose down wards, if i park her level or nose up, no start. 

Edited September 6, 2025Sep 6 by Leonie Swart

Hi,

There's likely to be a small air leak into one of the fuel lines between tank & engine.  That allows the fuel to slowly drain back to tank overnight.

Could be very difficult to find as you won't see any fuel coming out of such a small leak.

My initial thought (having had a similar issue when parked with 1 wheel on the curb) is that you have an air leak in the fuel system.

If there's a transparent section of fuel line, check for any bubbles. There should be NONE.

Then it's a matter of finding the leak which can initially again, be leaking or cracked fittings, pipe or filter housing etc.

I don't know what @TomsFocus has said but that's my starting point......

Edit: Ha ha! he agrees!

My suggestion would be to use a vacuum pump (Mityvac type) and isolate sections of the system to see if they can hold vacuum. When you get to the faulty component, that won't hold, you have found it.

Plastic filter housing/fuel heaters etc can develop a tiny crack that you can't  see but are a common culprit (I have had two such instances)

Good Luck but rely on testing, not luck. 

I note you are new to the site so Welcome!

If you can't DIY, get someone you trust but don't let anyone start changing expensive components without proof. If they say "We can try changing" go somewhere else?