Hi, just wondering can anybody help .I have just purchased a v12 xjs 5.3 engine 1989,I am putting it on a test bed to see if i can get it going,can anybody advise me if i need anything else to make it start apart from petrol and water and oil of coarse, sorry for being so stupid, please help, kind regards David

 

Hi David

check several things when recommissioning a car that has been stood


firstly battery , make sure its fully charged and in good condition

next is the fuel , make sure that it is also good,

then check all the pies in the engine bay along with the oil level and coolant level

if everything seems ok then you can try to start

the first thing you should hear is the fuel pump in the boot come to life when the key goes the the accessory position , the pump is under the battery in the boot

if that hums, then you should have fuel pressure

so try and start the car

if it just turns over and over then you need to check spark

being a UK 89 car its going to be a Mirelli ignition , this is wired like two bolted together straight six engines ,

the coils are in front of the throttle capstan , and the modules are mounted on the radiator cross member , either of these could stop the car from running correctly

injectors are controlled by an ecu in the boot to the right of the battery under the rear wing , and there is a module behind the right hand headlight that allows the injectors to fire ,

if any more than this then we need to get technical

good luck

BB

 

Hey David! Good luck with your purchase. I have always recommended a compression test, before, during, and after you get the car going. These numbers give you a reference point. If your car has 0 compression on one cylinder, there is a very good likelyhood that the car was parked due to a dropped valve seat. If this is the case, removal of the engine, is my recommendation. Much easier to work on, as you can pull the heads easier (although not a easy job) (You Tube it!).
One fellow on this list spent a lot of time and money coming to the conclusion that the engine wasn't worth saving. The car was is very poor shape, so add the two together, and I think he abandoned the idea.

Anyway, a compression test can be done very inexpensively, in a couple of hours. Write your findings down. The V12 is easy to keep up with as far as cylinder identification. 1A is the right front cylinder, then 2A, 3A...so on down the right side, then 1B is the left front, 2B, 3B, ...down the left side.

You are amongst sympathetic friends here, so no question is dumb. Can't imagine owning a Jag without these guys!

 

true , a compression test will show much about the engine,

but , if it runs , and runs well, its something you can think about and not necessarily have to do

if it runs rough , check the electrics first, both ignition and injection

then turn to compression if it bangs, farts and sounds like a bag of rusty nails.....

but its just my opinion ,

BB