As Fraser said, NOT hard, just time consuming.

Make sure you get the 2 camcover gaskets, the 2 "D" seals at the rear, 2 inlet manifoild gaskets.

Whilst its all apart replace the injector hoses, and the other fuel hoses in the engine bay as well.

The 12 small injector seals will do no harm while they are out.

My STRONG advice is to really get your mind straight whilst doing this, as the openings for the inlet ports will be facing straight UP when all is removed, and any loose, errant nuts/washers etc will fall directly inside the engine, TRUST ME, and then the heads will be coming off to remove the culprit, and you will be happy, NOT.

Plug all those 12 holes as soon as the manifold is lifted off, and place ALL the nuts etc a long way from the engine bay. Look very carefully PRIOR to lifting the manifold, coz there WILL BE loose stuff in there from previous "mechanics" that have dropped stuff and never bothered to dig it out, these are the ones that will catch you out, they did me looooooong ago, HE rebuild followed, and NOT planned, so now I warn anyone that is prepared to listen.

DO NOT be scared, just be sensible, and thorough with your work ethics while doing this task.

 

Hi Grant, I have the car running pretty good now. Here are some of the issues that i still have.
Any cheap fix for the fan clutch?
I was messing with the center consol and the window lockout button hit metal and sparked and now I don't have power windows and the gauges don't work any more.
I have no dash lights.
I can't get the idel to slow down without plugging the hole at the rear of the drivers side intake air cleaner that runs to the metering valve. I adjust the screw on the valve and the idel doesn't change.
The climate controls do nothing, they worked before I had the short at the center

Any help that you can give would be great, thanks so much in advance.

Tom

 

I'm in a similar situation as this. Also on a 1978 XJ12L.

I'm trying to wake a car up that has been sitting since 1986. Both oil and coolant look new so someone may have taken a stab before me. All the plug wires were eaten away from rodents. I pulled the plugs, and poured marvel mystery oil and got the motor to spin after a couple of days.

I then replaced the plugs but while down there, I noticed that the rodents had gnawed away at the wires on the base of the distributor (right at the connection). Is a replacement harness available?

I do not see how you can disconnect the wires the distributor so I'm wondering what to do here.

When I turn the key on, i can see a spark from the coil as I turn the ignition on but that's it. There is no spark as the starter engages.

Should I not be seeing a constant spark from the coil wire as I crank the engine?

I want to sort the ignition out before I even start on the fuel. The fuel pump does not run right now which could be a relay or a bad fuel pump. It looks exactly the same as an MB d-jetronic fuel pump which I have had good luck with taking apart and cleaning.

 

See the bold replies above.

 

YEP, D-Jetronic is D-Jetronic no matter what car it is fitted to.

I would start with ALL the wires in the "V", and make real sure they are all in good nick, especially since rodents have dined on some, why not the others???. The EFI loom in the bottom of the "V" is well documented as a pain in the a^%e on any good day. Time spent here will definately save you some SERIOUS brain strain later in the process.

See my underlined in the above questions.

 

Hi Grant, my email is tom@perfectphoto.com. I would love a diagram and how un stuck the valve. All my fuse are fine by the way.

Tom

 

Grant

Thanks for your response. I'll get cracking on the wiring and also work on replacing all of the old rubber hoses in that area before i touch the pump.

 

Good idea.

BBQ Jaguar tastes pretty crappy haha, and the wallet gets waaaaay too much of a belting when that happens.

Pre HE engines are prome to fuel fires, so PLEASE take the time and do them ALL.

 

OK, got it I will find the paper and email tonight.

I would recheck ALL the fuses, with the ignition OFF, and with a voltmeter, touch one end of the fuse holder prongs, and note 12v, OK, now check the other end of that fuse for the same reading.

Now do it again with ign ON.

Some fuses are LIVE at all time, and some are IGN fed.

Do not be fooled by fuses, as I was when I was a lad learning, LONG TIME AGO, coz the bugga's will read OK, but fail when "loaded", so I always REPLACE them, and ditch the old one, NO exceptions.

 

I have a question in regards to the original post. I am working on ’78 XJ12 with the same fuel injection issue as the one in the beginning of this post. I can jumper the plug where the trigger board plugs into and hear the injectors click, so I am fairly confident that the amplifier, harness and injectors are OK. The issue is how to trouble shoot that 4 wire trigger board. The three wire was fairly straight forward and spelled out in the factory service manual. Because it used reed switches, it was just a matter of checking continuity across the designated plug ends as the magnet was passed of the switches, but this four wire unit with the one power lead is a different animal. Any idea how to bench test this out of the car?

 

Chris,

Never had to test one, never had one with issues to be honest. The main issue with 3 cars I dealt with over the years had issues with the magnet in the heel of the rotor. I established that fact with the dizzy cap off, and ign ON, and waved a "magnet on a stick" over the board, and heard injector activity. In all these cases the magnet in the rotor was not that strong, and a new rotor restored engine activity.

 

I haves owned two XJS's and still have one today and the only way to own one you must have Kriby Palmer's book called Experiance in a Book. The V12 systems are very similar and the trigger board test procedure is in there. This is where I found that you need different rotor for the four wire tigger board. Best of luck

 

Thanks you two for the info. I am going to defineitly try a stronger magnet to see if that will trigger those hall switches. That "Experience In A book" is a great resource.

Thanks,
Chris

 

Hi all.
I am in a spot of bother. I am 47 and a qualified mechanic but could use some advice. I found you guys from a Google search.
I am quite bright but know when to seek advice and this is one of those times.
So I don't intend to be a blow in type round here and have quite a bit of experience around Jag V12's, but certainly not extensive. I have rewired an engine bay fire in a pre HE XJS. Also I spent $5000 on a customers 85 Daimler getting it back up. And of course I owned a 76 SII V12 for 5 years and revved it 6000rpm every day of that 5 years. So you can tell I like V12's very much...

So where to begin...?
Some history I suppose.
I just purchased a 1980 Daimler V12 and it won't start no matter what.
I should mention I have a complete 76 SII V12 XJ as a parts car. When the motor spun a bearing 5 years ago I kept it because I knew one day I'd buy another one. Well that day has arrived.
This one I'm having difficulties with, the Daimler, was advertised on eBay about a month or so ago and I inspected the car before I purchased it. It ran when the auction was active. I offered him money for it prior to completion but he let the auction run to completion and it didn't sell.

We negotiated over a fortnight and I offered him substantially less than the reserve and he finally caved in an I got it for $1750. Body is good, interior is good, leather is good, has a sunroof too with a black vinyl roof. The car sat for 7 years prior to sale and has no drive in the transmission, but this isn't my problem. I knew this before I offered him money for it anyhow.

So I get it home, put 20l fuel in it and go to start it. Nothing. It almost fires, but doesn't. Try again then dead.
So fuel pressure is 29psi on both rails - OK.
Injectors pulse when throttle moved and pressure drops - OK.
Whopping spark from the ole Opus ignition - OK.
New plugs.
Pulled apart all amplifier/injector harness plugs and sprayed WD in there.
Checked Map sensor/coolant temp sensor values all - OK.

So then, this has led me to the trigger board. It is a 4 WIRE and crumbling on top a bit but appears otherwise OK. The rotor seems perfect. The cap seems perfect. The plastic trigger board screws are all good and didn't break off.

So here's the questions: will my SII 3 WIRE trigger board fit on a Series III Bosch D injection system ?
What is the purpose of the 12V wire on the updated trigger board ?
Does the SIII computer require the 4 WIRE trigger board ?
For the purpose of diagnosis could I fit the SII 3 WIRE trigger board and computer or am I going to run into harness difficulties in the boot when I plug the computer in ?

The Jag manuals for SII and SIII (I have them both) are decidedly nebulous on this matter. The SIII wiring diagram is so tiny it is illegible but I'm sure you all know this anyhow .

Of course any other suggestions are most welcome. I'd like to be a more permanent fixture around here as I have lots to offer as well as needing lots of advice too.
I intend to through a bit of money at this Daimler esp a TH700.

I can give advice on the ignition too as I fitted a GM HEI from a HE with trigger board to a pre HE and it was fantastic ! 0 problems from that I can tell you and quite easy to do.

 

Nice bit of hyperbole .

 

Hi all, this is my 1st post so my apologies if I've done something wrong!

Here goes:

Car has been stood for 8 years, so drained all old fuel and replaced, injectors refurbished, and new bio 100 fuel lines used, new battery, coil, Re-Opus H amp installed, fuel filter & fuel pump fitted.

Car will try and start just on cold injectors or with starting spray fluid, then that's it! Good spark from new ignition amp, coil is fine, but today tested all 12 injector connectors with ignition on, and with test meter red lead in either terminal and black to earth, they all showed 12.7V! Is this normal, and if not what is the likely cause?....................I need to hear this beast again, it's been too long.

Many Thx Dave.

 

Paul,

I did not see the tag on that post re your issues, sorry for that.

Did you sort the Daimler?????.

The 3 wire will fit and work, as long as the rotor for the 3 wire follows the 3 wire board.


The 4th wire is a 12v ign feed for the hall effect sensors in the 4 wire board.

The 3 wire board has "reed" switches that only require a magnetic field to switch.