I'm trying to move off a Sticky from Grant Francis on "HE12 XJS won't start". May repeat self somewhat and to slowly search other trhreads in XJS for clues. Using manyof Grant's documents for clues. I also consult Jag-Lovers site for documents and clues.

XJS is garage kept and hasn't been run since 2006. 52451 miles.

Didn't periodically start as I should have, so dead battery, old fuel.

Worked to confirm fuel flow to rail. I think I initially burned out orignal fuel pump doing this. I drained all old fuel and put fresh premium in plus some stabilizer given this is taking long time. I'm only in Maryland a few days per month and tough to work in winter even though attached garage.

So replaced fuel pump, borrowed battery, put added fuel filter between sump and fuel pump based on suggestion from somewhere. Seems that should have been a standard before the Fuel Pump. Replaced standard primary fuel filter. I confirmed clean fuel downstream of primary fule filter (below Pump) adn then confirmed I have fuel to Rail.
Have tried Starter Fluid sparingly and engine would start to catch and die. Working alone, tough to squirt and crank ignition.

Months back, Ignition ON, I swear Injector Connectors measured 12v on both pins on three random selected connectors on A ann B. Now A Bank has 12v on one pin of connector. Sometimes left pin, sometimes right pin (housing crescent groove facing UP). With my DVM, the other pin on A Bank will not settle on any value. The B Bank, I get 12 v on one of pins and 1.7 v on the other across all 6.

Will check and clean EFI Resistor Pack. Attempt to inspect loom or test . Found the TPS and Ign ON, measured about 140 mv (0.14v). I know that is not per HE 12 of 0.34v Grant calls for in his guide. My full throttle position yields 4.7v.

New and Old Fuel. [hey, I have 95 gallons in Boat from 2002, ugh!]

So end of July more trouble shooting. Will also try 9 volt battery across Injector pins to listen for click.
Oh, I did manage to pull on spark plug from A bank. Seemed to be dry after cranking. Also loosened injector nuts on that one and forgot to retighten....had a moment where engine almost fired with that still loose on a later date. Re tightened, and then nothing. Compression seemed good in that cylinder. Forget the reading.

Still trying to identify the Ignition Amplifier. Identified AAV. Have to identify CTS and ATS and ECU

 

Hi Jagvulcan22

After standing since 2006 The Injectors are probably all gummed up and need cleaning, especially since she runs on Starting Fluid

 

have a technique for cleaning teh gum out?

 

last month attempted to remove Resistor Pack to clean connections. Dang, need some fancy tools and adgile fingers to get that out. Tried the 9volt battery technique on Injectors to see if I hear Click. Really tough to put clips on the injector pins. Fuel Bar interferes with everything.

 

Hi jagvulcan

Considering the state of that Fuel, it certainly looks as if the Injectors have got all gummed up, especially as your Car hasn't run for such a long time

So I think that you are going to have to 'bite the bullet' roll up your sleeves and resign yourself to taking all the Injectors out including the Fuel Rail and clean them all with some of that Carburetor Cleaner by dabbing each Injector with a 9 volt Battery, so that you can get them all to Spray, though not for more than a couple of Seconds or you could burn out the Coils in the Injectors

Its not what I'd call a difficult job, although if you've never done it before, then it could take you all day or maybe even a Weekend depending on how you get on, although before you even Start this job, you really need to get yourself a Spare Injector Plug (ebay) so then it will be easier to get the Injectors to Spray with a dab of power from a 9 volt Battery PP9

The other thing you are going to need besides the Carburetor Cleaner are some 'Pics' or you might just go crazy trying to get those Wire Clips off the Injector Plugs and you will also need some New Injector Seals, unless you also want to put new pipes on all of the Injectors, in which case you can buy a Kit from Mr Injector on ebay

Removing and Cleaning the Injectors on an XJS V12

 

the Marelli has a quirk, if you have removed the air filter box's , and unplugged the left side air temp sensor, the car wont start, same for the water temp switch ( there are two , one for ECU one for dash light)

BB

 

My car will run without air temp plugged in. Meaning the sensor on the front end of the LH breather... I can plug and unplug it while the car is running w/o any noticable change. Jus say'n