So I have checked/cleaned the resistor pack as suggested. It was slightly dirty but better than i expected. In the boot, I cleaned the wire harness/plug that goes into the ecu, all of the relay connections, and the "interface" (small black box next to the relays) connections with terminal cleaner.

I also checked the voltage on each fuel injector plug and all of them gave me about 12.4v with the ignition turned on.

I unfortunately got no change whatsoever after trying all these things. I feel like i should mention there is a strong fuel smell outside of the car immediately after cranking it a few times.

Not sure where to go from here, but like I said before I am learning a lot about this beast.

 

Fuel or Ignition?

 

If im understanding the question correctly, I just had the key switched on when i checked the lead on the injector plug. With the key off i got no volts. I checked the brown and white wire, if that helps.

 

Remove both air filters open the throttle (WOT) then spray starting fluid into both chambers both sides close the throttle and try starting the engine see what happens

 

OK, reread all this one more time.

You have a good blue spark AT the coil lead, BUT, do you have spark AT the spark plugs themselves.

My reasoning is simple.

One of mine got hissy, and nothing to do with its female gender, just got hard to impossible to start.

Pulled the distributor cap, nothing obvious, except for a LOT of black dust on top of the rotor. Looked up inside the cap, and NO carbon brush, BUGGA.

Removed the remains of what was the brush/spring.

Ripped a brush and spring out of a spare OLD cap, inserted in the hole, refitted the cap, THE BEAST IS ALIVE.

Worth a look in my opinion.

NOTHING to do with closing the boot lid, but its a Jag, and you have learnt a heap about its moods in the last few weeks.

The smell of fuel after your starting attempts indicates fuel is getting into the cylinders, but no fire in the belly, and that is spark AT the plug related.

 

Got a few pops that were louder than normal after removing the air filters, opening the throttle, and spraying some starting fluid in there, but still no start. I will check the distributor next as per your helpful advice, Grant Francis.

 

If you have a good spark at the plug maybe your distributor has dried out in the heat of the valley and seized up causing the base plate to shift all the way around this will throw out the timing hence the popping noise (ignition with the exhaust valve open) engine should have ran for a few seconds on starter fluid, never had a V12 I could not get started and running.

 

Pulled the distributor cap. the vacuum hose that connects to the side of the distributor was disconnected. Attached are photos of what I found:



the plastic vacuum hose fitting fell out when i removed the cap, i have since put it back in.







on this last one, more of a curiosity than anything...the two green wires near the throttle have never been connected to anything, yet there are clearly 2 places for them to connect to. could somebody possibly help me identify these wires? the come off the ignition amp.



i labeled all the wires as i was disconnecting it, of course and plugged the vacuum hoses back in. unfortunately no change. i plan to test each plug and associated wire when my assistant (wife) gets back from her business trip.

As always, thanks for the help.

edit:

Forgot to add that i also checked the coil (primary) as suggested in some other threads and with ignition switched on I had 12v from positive terminal to earth ground and 12 volts from neg terminal to earth ground.

 

Those two green wires do not come from the ignition amp. They belong to the transmission kick-down switch. The switch is located under the metal plate that is attached to the throttle cable. If the switch is missing then you need to order one.

Mark

 

I have read through this a couple of times now, still with no hard and fast explanation of what could be happening.
I’m going go out on a limb here, just from what has being said and done so far and the pics you posted. Back to basics
Q. How old is fuel?
Q. Was it sitting a long time in the weather or under shelter?
Q. Do you simply have a tank full of water?
This is basically the only thing that comes to mind at the moment.

 

The fuel is about 1.5 months old. I have tested the fuel for water and it was fine. It was and still is sitting in a garage, so not out in the weather at all.

For those that are curious if this is a heap or not, here are some photos of the beast in question:



Like I said, I still need to test the spark plugs and individual wires. Also, aside from checking for a blue spark on the coil wire, can somebody tell me what the voltages should be on each terminal of the main coil with the leads both connected and disconnected? I have searched around on the forums and have come up with some conflicting/unclear information.

I actually have a fair bit of time to work on the thing in the coming weeks and I really want to bring her back to life!

Thanks!

 

Looking good.

An XJ-S is NOT a heap, EVER, and anyone that refers to one as a heap needs it removed from their ownership, biased I am, seriously.

Those 2 hoses on the side and cap of the distributor, are NOT vac hoses, They are purely distributor vnting hoses. One end is open to the atmosphere with a small plastic filter shoved in its end. The other end is in the "draught" section of the AAV hose that travels from the rear of the RH air cleaner backing to the AAV inlet.

Refit that cap, refit the plug leads in thr correct order, and grab an old spark plug, any will do, and insert it in the end on the easiest lead to get at, and sit the side of it on the cylinder head, and crank the thing over. Do you have spark AT the spark plugs, and a good fat Blue one at that.

The fact you have spark AT the coil lead going into the cap indicates that the amp/coil. etc is all doing what it should.

You have fuel in the cylinders, coz you say you can smell it.

There is simply nothing igniting what is inside the cylinders.

So, back to basics, new spark plugs and leads. I run NGK BP6EF in the HE, and Magnecor leads, and have never had issues.

The plugs in a HE can foul VERY quickly with numerous attempts to start it without success, its just how it is. You are only runng 11.5:1 comp ratio in the States, we run 12.5:1, and if that sucker dont start readily the plugs are fouled, and they simply will NOT ignite the fuel, then add the Ethanol you guys are forced to use (we dont have it), you really are pushing the limits.

My rule down here for any HE is that when you start it for any reason, TAKE IT FOR A DRIVE, do NOT simple start it to move it for access to something else and shut it down, they will foul the spark plugs. If you dont want to drive it, let it run until the temp gauge at least starts to move. I have 2 I care for belonging to elderly owners, and they constantly start them just to see if its still OK, and then the next round it runs on 10 or less, or fails to start. Clean the plugs, or fit new ones I have on the shelf, and they always fire first hit of the starter. Mine sat for 2 years, company car, and I simply put fresh fuel in it, primed the system, and on second rotation of the engine it was alive and well.

 

Totally agree with Grant, Thats no Heap you have there! they are a superb motorcar and simply something very simple has gone wrong with yours. Logic tells us if you have fuel and spark you have ignition, simple as that. I wount go over covered ground do what Grant has suggested in his last post, it should run especially if it was running.

 

The easiest thing to check for a spark, forget voltages at the coil and plug wire testing pull a plug wire off a plug any plug use a spare spark plug any spark plug hold it with pliers or a rag against the engine block or head get someone to turn over the engine do you have a spark?????? I am beginning to think this thread is a scam to collect as many replies as possible K.I.S.S.

 

interesting read, tacking a ECU (maybe) issue just now, few interesting points here.

 

Sorry if this is getting a bit drawn out at this point. I am admittedly a novice when it comes to working on this vehicle. I got a chance to dig into it again today with the intention of checking for a spark as you and everyone else suggested but of course I left the battery hooked up and let it drain out since the last time I was messing with it, so I felt pretty stupid about that, haha. Currently it is hooked up to the charger.

Since I couldn't check for the spark today I thought I would check a few other things, most notably the Centrifugal Advance as described in "The Book." Pretty sure its bad news there. I tried rotating the rotor the 11 degrees counterclockwise as suggested, and eventually it did move but not without some gentle coaxing. It moves, but not easily, and does not snap back to its original position (assuming it is supposed to do that). The book informs me that symptoms of this problem are "lack of power at higher rpm and a nasty tendency to overheat" but I never experienced any of those. Could this be part of my no start problem or something else entirely?

moff1959, I promise I'm not trying to collect replies! Will report back about the spark asap.

 

Battery draining whilst connected for that period is indicating other issues, later sort out, lets fire the thing up first.

The centrifugal advance will NOT cause a NO start, EVER. Remove that rotor button, dont break it, and drop some oil into the centre of the exposed shaft, (in these cases I use ATF) let it sit, have a beer or 3, work that shaft, and keep working it, and it WILL free up. It is a time thing, so let it soak for a while, you got time, the battery takes 24 hours to charge.

Once its free, refit the rotor and cap, and remember to oil it again in 3 years time.

 

While you have things stripped out, I would simply remove the Dizzy and give it a good clean out and reset it, just make sure to put it back it back in the same position, its probably overheated and starting to rust up a bit. I removed the electrical components on mine and cleaned it out with kero, then sprayed a little high temp non drying grease on the moving parts.
This is the one of best things I ever bought for my battery, because my car isn’t driven all the time it kills the battery, just the clock working a door not closed properly even the glove box left open will empty a good battery in no time. This actually bought my battery back to full life, I have one on the Jag, Bobcat, Boat, as I hate buying new batteries because they die from not having a constant charge trickled into them.
Solar Panel 12V 10W With Alligator Clips Battery Charger Genuine Suntech Cells | eBay

Again what Grant has written is correct, the dizzy advance will not stop your car from starting.

 

Remember, 50% of your maintenance is caused by 50% of your maintenance. Don't do "too much" in an exhaustive search as you may create new demons. All advice here is well intended but some can be ill advised ( not singling anyone out) be methodical, be patient and do one thing and re-check for firing. Then move to another, avoid doing multiple things then rechecking. If your car ran fine before with the vent lines and kick down wires removed then we know those are not it as they have probably been that way for some time, closing the boot didn't make them fall off. Don't get yourself in a "chasing your tail" mentality where your unsure if something you've done has caused a new issue. If you know someone with an XJS it'd be nice to be able to first swap out the coil, then the AMP, then the ECU etc one at a time then recheck for fire after each ( those are easy swap out items)

 

Sorry I haven't posted this sooner, but I finally was able to test for a spark and I am getting an orange spark on two different wires.

Going back to the lead from the main coil, here is a video of what I am getting there:
(sorry for the bad quality cell phone video)
main coil.mpg

Other than the test I just did on the main coil, what voltages/resistances should I be reading when I measure it?

Sorry this took so long, things have been a bit hectic around here.

edit: changed from no spark to orange spark. used an actual test lead to ground the plug instead of a spare bit of metal.