Hi, finally got a chance to have a look round my barn find today! My first job is to get the motor running again. It fires up for a couple of seconds when spraying easy start up the intakes so I know I have a spark and I also cracked of the fuel line at the rail and the fuel is up there with good pressure. So I'm thinking it must be the injectors not working? I haven't had time to remove them and check today but I'm guessing that's it. Does anybody know why or what part could be making them fail? Anyhelp is greatly appreciated.
Matt.

 

First.....Have you checked for supply voltage at the injectors? Key on, engine off, you should have 12v at the injectors


Also....


Problems with the infamous shielded wire are common. Here's some reading (probably more than you wanted) and an archive search will reveal even more:

https://www.jaguarforums.com/forum/x...-grant-167093/

(The conclusion of this ^^^ thread is that the injectors themselves were stuck closed due to prolonged storage....but a faulty shielded wire is still a common issue worth checking)


Also......

Poor/dirty/loose connections at the injector ballast are also a possibility. There's a good thread illustrating the problem


There are other possibilities but the above is as good a place to start as any, IMO

Others will chime in

Cheers
DD

 

Take a look at orangeblossom's thread on re-starting his car after a 6 year wait. All dealt with there and very good info and pics too. The injectors are dealt with about here onwards:
https://www.jaguarforums.com/forum/x...-122634/page8/
Greg

 

Thanks, will look into all these. The cars been stood for 13 years so I new it would take some sorting out! It ran fine before storage though and even had a service just before new filters plugs and oil etc.
Thanks again, Matt

 

Doug had all 12 of his injectors stuck....... It's a possibility

 

Hi Matt

My XJS V12 had been standing for 16 years!

So similar to yours and 6 of the Injectors were gummed up.

Not hard to fix, my 'guess' its probably that.

 

Cheers, so when I get chance my first job is to check for voltage at the injectors and also the condition of the wires. Then if that's all find whip out the injectors and test them. If there blocked what's the best method of cleaning, do I just need to give them a good soak in carb cleaner. 5 minute job I'm sure....

 

Hi Matt

It's not 'Quite' that simple!

I took out the whole Fuel Rail with the Injectors Still attached and then filled the Fuel Rail with Wynns Carb Cleaner.

Then introduced some low pressure Compressed Air (Where the FPR on 'B' Bank screws in) and then Checked the Injectors one at a time, using a PP9 Battery and touching the power on for only a Second, as any longer and you could burn out the Coil in the Injector.

They will either Spray or they wont.

On some I had to give them a one second touch of 12v instead of 9v and others also needed a 'Tap' with a small hammer on the metal part.

Also give them a head on Blast with Wynns Carb Cleaner on the Tips and you should hear them Click as you do that.

Just keep repeating that process and eventually you should be able to get them all Spraying.

Before you do any of that though, its probably worth removing the Silver Box by the Headlight Nacelle and Cleaning the Plug and Socket @Greg. As that is maybe all you would need to do.

Then 'Flick' the Throttle Capstan round and hopefully you will hear the Injectors 'Click' and then She 'might' Start!

If no dice then it could be a case of gummed up Injectors.

Stay away from the 'Easy Start' or you could wipe the Oil out of the Bores, which would not be good.

You WON'T even need to 'dope' her with a drop of Petrol down the Air Intakes.

With a Fuel Injected Car, if everything is working then She should 'Start on the Button'

 

Ok maybe 10 minutes, will hopefully get back up to the car this weekend and have her running! This is definately going to be a long resto, when I first saw the car I thought 'get it running fit new brakes and give it a respray job done' but the more I look into it the more I want to do everything right. That rear subframe assembly really is a work of art so I'm just gonna have to remove it and give it works! Its just going to go on & on. No time frame though so what the heck, and what else can you find out there with a V12 for virtually free to restore? One job at a time though.
Thanks for the replies, seems there is a world of knowledge on this forum so I'll no doubt be picking your brain's again & again & again.

 

If you tackle it with this attitude you will be successful. Do the job right and do it once. Good luck............

 

Going up to the xjs again tomorrow to try and get it started! I now know the injectors all work fine and not stuck using a 9v battery to test them. So its definately looking like the pulse wire. I think I know wire it is coming from the amplifier on top of the inlet and it does look worn and I can even see a small crack in it just before it connects to the amp

 

Ok so not had any time for the xjs lately until yesterday. After I put the injectors back in I put a meter on one of the plugs and turned the ignition to on, no reading until I crank the engine over when it gives intermittent readings of 6v & 10volts whilst turning it over. Is that normal? Then I looked at the ignition module on top of the inlet but am unsure which is the pulse wire? There is a single white wire which comes out the back next to some others and this goes to a bullet connector and then turns into a double wire which dissapears into the loom at the back of the engine but has no outer metal mesh wire. Or there is a twin plug which goes in the side and this has an earth wire which connects to one of the mounting bolts on the module.


Pic A



Pic B

 

Pic B is the pulse wire to the EU. Pull that bullet connector apart and clean it. The shield starts inside the thicker wire with the black cover. If the white insulation on the bit of wire you can see is still flexible and not cooked, the chances are it is OK.


The plug in the RHS of the amplifier (the black unit) comes up from the bottom of the dizzy, and hs a rubber plug towards the dizzy end, which is quite hard to separate. Check this wire is not cooked too. It may well be that the coil is not good, or the amp unit itself, so check for a decent spark at the plugs, which you should change as well as the HT leads. Also service the dizzy cap inside, or renew it, and the rotor. Even if any of this is somehow still working, they will not for long.
Greg

 

Thank you, the white wire is not flexible and has cracks on that part although the wire itself is not broken, I checked the wire further back by slicing the cover and the 2 wires here look fine and are flexible so will I be ok just replacing the white single section? I know the car has a spark as it ran on easy start for a few seconds no problem but then dies when you stop spraying it in. All I want to do is get the engine running so I can check it's ok. Once I know that's good I can start a proper resto but no point in doing anything until I know the motors good.
Thanks for the help.

 

Replacing the brittle section is fine. But the shielding must be kept intact and the earth blob of solder and earth wire you will probably find not disconnected. The engine will be fine, but my experience is that you will be very lucky to get it running well unless you do all the needed renewing systematically and thoroughly. But if it runs on ether, you have a fuel problem, so it is a bit unlikely the ignition amp is faulty. The first thing to do is, ignition on, check if when you flick open the throttle capstan with your hand, the injectors click once. If they do, test again for fuel pressure at the rail. If you have it, pull some injectors and see if they are actually spraying when you turn over the engine.
Greg