Engine Bay Upgrade - 1979 Pre-HE

[ptjs1]

There's a mantra oft quoted on one of the US-based Jaguar Forums about maintaining the engine bay components of a V12 XJS - "Do it once, Do it all, Do it right".

And with the earliest XJS nearly 45 years old, it makes a lot of sense. A Complex fuel injection system, deteriorating fuel injection wiring, hardening rubber fuel and coolant hoses, clogged radiator etc etc. All of these are issues that should be addressed. An overheating V12 is a huge bill on the way. An old fuel injection system is a fire waiting to happen.

So, although my pre-HE runs very well and has clearly had some money spent in the engine bay in recent years, I decided it was time to take a deep breath and do the whole job. My starting point is to do the following

- replace all coolant hose
- replace all fuel injections hoses
- get injectors cleaned
- fit a replacement injection loom
- replace yellow fan and viscous unit (a touch noisy anyway)
- flush the radiator (but probably a recore)
- replace thermostats
- replace inlet manifold gaskets (I'll use x300 ones and cut to fit)
- replace oil pressure sender units
- possibly change cam cover and D-seals (apparently changed 10k miles ago?)

As many of you will know, when you look at the engine bay of an injection V12, it's really quite daunting:

I've started the job and have got the coolant drained and one side of the injection system removed. It's quite a complex and time-consuming job. I'm keeping a very detailed log of every single step to strip it down, which I'll publish at the end.

So as at today, I've got to this point:

I'm already starting to think ahead on the purchase of parts and wonder if anyone has any views on buying the following for a pre-HE

- Coolant hose set. I'll either go standard or Kevlar.
- Fuel injection hoses - Buy a full kit, or buy a length of pipe and all the separate seals, ferrules, pintle caps etc?
- Injection wiring loom
- Inlet manifold seals (X300 and cut is apparently the best way to go)
- Cam cover seals
- Black radiator fan and viscous unit
- Thermostats (apparently getting the right ones that have the correct bypass pin length is very difficult)

As always, any thoughts very much appreciated.

Thanks

Paul

[davidr]

Paul - an interesting project. Well done for taking it on and your determination to do it right.
Please keep us posted and take plenty of pictures.
I'm sure you'll know what I'll ask for next! Magazine article please!
Best wishes
David

[1977XJS]

All of us Pre HE owners are watching with interest, good luck, regards Richard

[PaulGover]

I tried some "Kevlar" coolant hoses some years ago, and they failed in about 1 year. Useless. Things may have changed since then, but unless anyone says to the contrary, I'd recommend sticking to the originals. Can't speak about any of the other bits except thermostats, where either Jaguar Classic Parts or SNG Barratt would be my first points of call.

[ptjs1]

Tks for your comments, guys.

I had dismantled the A-Bank by removing the fuel rail and injectors and then subsequently the inlet manifold. I then decided that I might try and do the B-bank as one unit.

With the fuel injector wiring disconnected and the pipe connections to the AAV and the large vacuum connection pipe on the rear of the manifold removed , I then set to with the inlet manifold nuts and washers. It needed very careful use of my magnetic stick to avoid the nuts and washers falling into the V, but I managed to get them all out. Then with a bit of wiggling, off it all came!

I do like the idea of re-assembling each of the refurbished sides on the bench and then installing as complete units, but access to those manifold nuts is VERY limited when all the fuel rails and injectors are in place. One to consider over the coming weeks.

When you see the engine without its complex fuel intake arrangement, that V12 really is a beautiful sight, isn't it?

The next step will be to remove the radiator and all coolant hoses.

Paul