Easiest way to tell would be to unplug the injectors, put some 12V lights to them and see if they Flash when turning over... Heck, even to one or two would do.

 

Hi Daim

That sounds like a good idea, as otherwise it is quite hard to tell what is happening

 

Hi Warrjon

I'm not really sure if they're firing or not but She's definitely trying to Start and so I might try Daim's idea with the lights

 

Glad I could help
As Jagboi64 mentioned, injectors can be removed with the fuel rail as a unit, they can be just pulled out of the manifold, the o-rings seem to be much better quality than on the older AJ6 engines and don't have to be replaced unless they are clearly brittle/hard/leaking/etc. Mine were perfectly fine after 20 years when on the XJ40 they were clearly hard and past its use by date
Injector signal can be checked with a noid light tester(~£15 on eBay, not sure a normal bulb would work here), problem is that the signal might be there but injector might be stuck, a good idea for this would be to connect 12V to the injector for a second and hear whether its clicking or not. If it clicks - it should be fine, might still be stuck but at least it fires and it should clear with enough pressure in the rail eventually before a further clean up. You can get a plastic adapter for a can of eg electronic contact cleaner on eBay(~£3) that goes over the injector and a bosch plug(~£3) to temporarily connect 12V to it, eg eBay item number:263745147704. That's the only way to check these properly(past sending them for pro cleaning, which is ~£15 per injector) and you can observe the fuel pattern, whether they open correctly and are not leaking when closed.

 

Hi Katar

Thanks again for your very detailed and ultra helpful replies, as I know nothing about these Engines and no idea what a Noid Light is but thanks to you and others, I'm closing in on the problem

Here's what I did and what happened:

The Coolant Temperature Sensor, was reckoned to be the possible cause of a 'No Start' Problem, so I put a Bridge across the Female Sockets and then spun the Engine

Where She went from trying to Start to not wanting to Start at all! (She didn't fire once) in which case it would appear that the Coolant Temperature Sensor was OK and so I reconnected it as was

Next I tried out Daim's suggestion of using a 'Bulb' and although you may have got there first by mentioning a 'Noid Light' at the time in question, I didn't have any idea at all what a 'Noid Light' was

And so I went with Daim's idea of using a normal Bulb, which I connected to the Plug of No1 Injector, where after 5 revolutions the Light Bulb Lit on the 6th! (Genius idea Daim!)

But when I tried to do that again, in order to make a Short Video, the Light Bulb didn't light!

Maybe a Wire lost contact of maybe it blew a Fuse but the fact that it ever worked at all, is very much leading me to think the Injectors are getting a Signal

Or at least they would be, if only for one thing!

The 'Pins' on the Injectors, take the word Corrosion to another level, as they are almost Black!

Which could easily be the Cause of the 'No Start Problem' very, very, likely I would think!

So I am going to Clean the Injector Pins and then try her again and if that doesn't work, then I'll take out the Injectors and give them a Clean

I've got some Electrical Cleaner and also a Spare Injector Plug, which I used to Clean the Injectors on my V12 'Cherry Blossom'

The light at the end of the tunnel, is starting to look a bit brighter, with hope now in sight!

 

Noid light is just a fancy bulb to check injectors, normal bulb, normally I don't think that it would work due to signal frequency.

You can view what it is and how it works eg here:


A set on eBay cost ~£15 and its well worth having, especially with multiple cars

Also, as I said earlier you really need an OBD scanner for this car.

No idea why connectors would be dirty though, this is puzzling!

 

Hi Katar

No me neither but just take a look at this Pic

 

What does the female side look like? This could indeed be the source of your problem!

 

Hi Katar
Hi Vee

Cheers Guys!

But I think I've finally managed to track down the problem (although I think I may have said that a couple of times before)

Having taken the Electric Plugs off from the Injectors, I tested each of them individually with a 9 Volt Battery and then a 12 Volt Battery and could not hear any off them 'Click'

So I pulled the Injector Rail out of the Car together with the Injectors (not all of which came out when I pulled out the rail)

Taking out that rail was a real nightmare, as it was in there so tight that I had to lever it out with a piece of wood but having eventually managed that, the next job will be to Test them while they are out of the Car

So the Plan is to put them all back on the rail and then block up one end and then fill the Injector Rail with Carburettor Cleaner and then apply low Air Pressure to the other end of the Rail

Then using my Spare injector Plug, give each of them a quick 'dab' of 12 Volts and then see if they squirt, or if they are going to need replacing

 

 

Hi Vee

That is very interesting!

Because I've found the problem and a very expensive one too!

As having tried everything that I could think of, I decided to delve a bit deeper and pull out the Fuel Rail together with all the Injectors and they were in there really tight I can tell you

And then I decided to Test them on a Homemade rig and you'll never guess what or maybe you would, 4 of the Injectors were burnt out!

(Just like you just said)

I wonder how many people have ever thought that might happen?

You run out of Petrol = New Injectors!

Your Fuel Pump packs up = New Injectors and a New Fuel Pump!

And while I'm sure there may be times when you can get away with it, there must be an equal number of times when you can't, as it certainly looks like I'll have to replace everyone of those Injectors on the Fuel Rail

As when I tested them on my Rig only 2 of them were working, so that was probably why She was trying to Start but wouldn't pick up

Where as for the back story, 'Carmen' was an impulse buy, which then just sort of left me with another XJS I didn't need, as I've always thought She was too nice to use

And lack of use was certainly what must have caused this problem

 

Hi Vee

It looks to me like you have gone and Nailed not only the 'past' but also the 'future' as having had a chance to think it over, for one reason or another it seems a lack of Fuel was causing the problem

And as you so quite rightly say, I need to make sure that another new set of Injectors doesn't burn out and go the same way, so the first thing I am planning to do is hang a fuel pipe over the side of the Engine Bay

Then turn the ignition key on and off a few times, to make absolutely sure the fuel is getting through where I can then pump some into a Jar

Does that sound like a Plan?

Thanks for your Help and also to Katar, as you have both been amazing to a 'Newbie' like myself who has never worked on an AJ16 before

 

Have you measured them with an ohm meter, if they are shot then they will be open circuit. Not sure on the exact resistance of the I6 injectors but they should be somewhere between 1 and 4 ohms.

If the R is ok then the injectors may be just gummed up.

 

I'd very surprised if they were burnt out, they can take a fair amount of abuse before burning out the coil and obviously that doesn't happen normally while they stay attached to the car due to high frequency signal when you power them. Lack of fuel would not damage them here.
What happened here, is the pin is probably seized in the injector from the dried up fuel deposits. With some of the injectors its pretty obvious how to open them up to free it but with this Bosch one I have no idea how. I suspect the top plastic bit either unscrew or can be lifted up if you drill(?)/punch the metal bit in the hole in the middle.
You could try tapping them lightly with the power applied. This might help, just use a screwdriver handle not a large hammer
If you decide to replace them, there is plenty used ones on eBay and not that expensive and if you decide to bin these, try opening up one before you do. It would be nice to know how to open these and I suspect one will have to be sacrificed to find out how.
Alternatively might be worth asking someone from injector cleaning services whether they can fully refurbish these inc opening them up.
There is also a set of working used injectors on eBay now for £25, eBay item number: 253814742383

 

Hi Warrjon

That's a great idea!

I never thought of doing that

 

Hi Katar

Another great idea! even if one has to be Sacrificed in the cause of R&D

Many Thanks for that suggestion

 

 

There is a 3.2l AJ16 I had one... In my X300. Just like there is a 3.2l AJV8 as well It is the smallest EU engine in the X300... My signature shows the XJ6 from 1995 with a 3.2l AJ16. Just because it wasn't sold in the States doesn't mean it was never sold

 

Oh, and yes, the 3.2l injectors will work on a 4.0l as they are both the same, when used on an AJ16. Both have the LHE150AA injectors.

As long as they are LHE150AA types, it will be fine...

 

'Carmen' No Start Mystery finally solved! (XJS 4.0L with AJ16 Six Cylinder Engine)

Coils burned out on 4 of the Injectors of my 6 cylinder AJ16 Engine, which may have been caused by blocked filters in the top of the Injectors, which in turn resulted in Fuel Starvation causing the Injector Coils to burn out

When measuring the resistance on my Meter, 4 of the 6 Injectors had gone 'Open Circuit' leaving just 2 of them working which was probably why she sounded as if she was trying to start

Full story with Pics on my 'Cherry Blossom' restoration thread on Page 95 and here is a link to that page: 'Carmen' No Start Mystery Finally Solved