Does anyone know if the uppermost o-rings (circled in red below) for the injectors on a 1L Ecoboost are available on their own?

They are available as part of a kit (part code 1764075) which include the washer, spring clip and teflon sleeve but I'd prefer (cheaper) just to buy the o-rings on their own if at all possible.

I believe their dimensions may be 6mm ID x 12.8mm OD but I'd be hesitant to go for a generic o-ring of that size given the importance of the application.

Ford does not supply these O-rings as seperate parts. These O-rings are only available as part of the fuel injector assembly or seal kit.

Many other car manufacturers use the exact same type of Bosch fuel injectors (for example Volkswagen and all derivatives). You may be able to find the seperate O-rings from another car manufacturer.


Never use generic O-rings for such a critical application unless you know the exact dimensions (O-ring dimensions are always specified as inside diameter x cross section) and the material specifications of the O-ring. There are literally dozens of different O-ring material types, compounds and hardnesses.
 

Thanks Wilco, pretty much confirms what I thought. I thought it worth asking in case they are the exact same o-ring as another Ford model which, for whatever reason, does happen to have the o-rings available separately and a corresponding part number for them.

I did start to look at cross-referencing injectors from other makes but tried to keep reminding myself that even though spending £25 on a full Ford kit just for the o-rings doesn't feel like good value at least I'll know they're exactly the right ones, and maybe I might need the remainder of the kit one day.

All said and done I might not actually need them. I took the fuel rail off the other day and having put it back today found that when the low pressure fuel pump ran (when opening the door) some fuel leaked out of the rail around one (or more, hard to tell) of the injectors. When I start the car tomorrow and the high pressure pump kicks in then I'm hoping the current o-ring will then get itself properly seated and form the seal as intended.

Edit: Have decided on Plan B - I'm going to remove the rail again tomorrow (fighting the temptation to pop out now at 2130!), double-check the o-rings are seated properly and I didn't damage them refitting them 'dry', and this time will apply a small amount of lubricant (likely vaseline as they must of course be resistant to petrol) to help them bed properly before putting it back together again. I think I'd feel better doing this rather than taking any risks of the ridiculously high rail pressure spraying fuel everywhere!

Just to close this one off; it's all sorted now but the phrase if it's not one thing it's another springs to mind!

Having decided to remove and refit the fuel rail I set about first taking the ignition coils off. They looked slightly different than usual once removed and sure enough I found that all three rubber boots had remained inside the cylinder head still hugging the spark plugs! I wrestled them out with some pliers and found the reason they'd stuck was because they had swollen up - almost certainly due to them having sat in a bath of spilt fuel yesterday.

Again, this isn't a part that Ford sells separately (you need to buy the entire coil) but fortunately I've got a spare engine (bought for a quid off eBay back in 2017!) and so took the boots off its coils. You can see how swollen mine (left) had become in comparison:

Anyway, on to the injectors, with the fuel rail removed I could see straight away that two of the o-rings were damaged and one was even a slightly different colour for some reason (for what it's worth all three looked particularly 'dull' too):

(Actually, having now seen the photo I see that all three have bits missing!)

Whether that was due to me refitting them dry and consequently pinching them in the process, or perhaps their age (13 years) and them not taking well to being disturbed again (I previously removed the fuel rail a year or so ago when I changed the timing belt) I don't know. Perhaps a bit of both. I checked the condition of those on the injectors of the spare engine and they looked absolutely fine so I swapped them over but applied a bit of vaseline to them this time to help with reinstallation. I could feel how much easier it was to refit the fuel rail having done this so perhaps it was indeed me pinching them due to their dryness last time that caused the failure.

I took the car for an Italian tune-up down the bypass and there's no leaks, which at nearly 2000psi would presumably have become quite readily apparent!

Replacement genuine Ford parts are often a tad pricey I use OEM  parts and find them almost the same. A bit of lube ? I use brake fluid. Seems ok on rubber and does not mind heat.

Yeah I think anything would be fine in practice, not least given these are seemingly made of a very robust material (not necessarily against physical damage but chemical attack, particularly against petrol). It looks like many use a little dab of engine oil. Anything just to help it initially slide and seat properly I suppose - it's not a moving part after that.