I’ve installed all my fuel injectors after having them serviced, and am ready to tighten the brackets that hold them to the engine. Each bracket has (2) 1/4x28 nuts. I like to do things to spec, but I can find no reference to a torque setting for these nuts. I have the Jaguar factory manual for my 85 XJS, but it makes no mention of this specification. If I can’t find anything, I will just tighten them the same as I would any 1/4" nut, keeping in mind not to go too tight and end up crushing the 2 new injector seals. But before I tighten them, I thought I’d ask if anyone has the specs. Thanks in advance,
Hmmm… I don’t have specs here. May be able to find them later but you won’t damage those seals or bushes. The clamping plate will bottom out on the manifold at the right distance to press those injectors into the seals by way of the aluminum surrounds on the bushes.
Thanks for your reply. I also suspected that the seals probably wouldn’t be damaged by overtightening the brackets because the brackets look like they would bottom out first, but I needed to be 100% sure. It takes a long time to carefully remove all that is needed to get to the injectors, and in doing so I discovered some nasty surprises like a crumbling fuel injector harness. I don’t ever want to have to do all this over again, which is why I wanted to get the injector brackets’ torque specs, if there are any.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
4
If I can’t find anything, I will just tighten them the
same as I would any 1/4" nut, keeping in mind not to go too tight and
end up crushing the 2 new injector seals.
Negatory. Tighten those nuts down fully. The injector seals are supposed to
be compressed.
True, but since torque settings are based on bolt diameter he should be able to use it as a reference. I would say 9-11Nm would be a wise choice. I posted that after disassembling the cooling rail on my 1989 that someone heavy handed the bolts on the thermostat housing and stripped out a couple of the threads in the aluminum housing because they didn’t at least try to torque them. I am a firm believer in following the torque procedure whenever possible. The damage that can be caused by over tightening can cost a lot to fix.
