Hello, I have a Jaguar XJ12 5.3 HE from 1989 with the Lucas Ignition system, I am currently at a hold because I have no idea where to look anymore, I have replaced the fuel tanks, fuel pump, fuel filter, took out the injectors and had them reconditioned, changed the ignition amplifer, took out the resistor pack and had it cleaned and checked, took out distributor and claned it, checked for fuel pressure I have 3 bars, checked for spark there is spark, the only thing I haven't checked it's compression, the engine starts on starter fluid but won't run on itself, there was an instance once when the engine started alone and it ran for 3-5 seconds and died and since then it won't even start on starter spray, I am have tried everything and anything but at this point I am starting to give up, especially after seeing it had 3 bars of constant fuel pressure and spark and no start. Is there something I have missed? All injectors are clicking I listened to them using a stethoscope. I was thinking about the pickup, but the distributor was replaced with a new one some time ago, and we checked the pick up and it seemed fine.

 

Since it will not start, have you:

1. removed a plug and checked that it IS sparking when the engine is cranked and the plug is earthed to the engine?
2. removed one of the front two injectors and while the engine is cranking, the injector pointe into a jamjar, checked that fuel is being sprayed?

 

1. there is spark on all banks

2. bank a keeps spitting petrol through the injectors on bank A but on bank B it spits only when I turn the mey into position II but when I try to run it it doesn’t activate the injectors on Bank B they sit dead in the water not clicking or anhthing but they click then I put the ignition on.

 

One thing to think of If it starts with starter fluid but not without it could be the timing. Starter fluid doesn't care about timing. It's just in there.

“Has spark” is not enough. It needs spark at the right time.
Since the distributor was removed/cleaned/replaced, I would absolutely verify:

Rotor points to #1 at TDC compression.
Firing order is correct.
Plug wires are not shifted around the cap.
Timing light flashes consistently while cranking.
Timing is somewhere reasonable, not wildly advanced/retarded.

 

any pin points to the top before dead center? I am going to try to do it these days properly from
what I saw I have to turn the engine by hand 2 times and set it 10° before tdc.

 

I think if you did not adjust the engine timing between the time it ran and did not run, timing is unlikely to have changed.
As an good condition HE engine will run on one bank, even if the other is not firing at all, I suspect even A bank is not running properly.
You have isolated the problem to a degree, being fuel delivery on B bank while cranking; I assume that when you said above: "when I try to run it it doesn’t activate the injectors on Bank B" you mean they do not fire while the engine is cranking?

If so, with a Lucas ignition engine, and with A bank firing the injectors a bit, and with all plugs sparking, this is most likely to be a fuel injection system fault rather than an ignition fault. It most certainly is not a compression problem.
It could be injection loom, car loom between the ECU and the injection loom, or ECU fault.
Injector loom failures are common, so if yours is old renewing it is always an important maintenancething to do.
Rare as ECU failures are, the can fail, so if you can find a known good one, I would try changing the ECU first.

 

My suggestions.

Stop throwuing stuff at it, please.

In the XJS Section, One Down from here, are many Stickies at the top. Get some drink, and sit and read them. Same car, only got 2 doors, AND, forget anything aboit Mareli. The S3 NEVER got that, it was a special gift to the XJS.

You say you have spark, I doubt it, or there would be a fart of sorts, even if the timing is out of phase. The HE needs a FAT BLUE CRACK of a spark to light it up, and anything less is playtime.

I have some PDF I will attach later, when I sort them.

The B Bank injector pulse MIA is a loom issue, and the loom section that travels under the AC Compressor is high on the suspect list. Even so, it should fart with Starter Ether.

Attach a Volt meter to the White wiire on the coil Pos Termonal, Ign ON, should be battery volts, or close. NOW go to crank and observe that Volts. It will drop a bit, but not much. If it crashes, the Ifnition Switch Electrical Section needs some TLC, PDF to come.

I will attaxh an ECU Pinout chart for reference.

Check the engine earth strap fiasco at the LH engine mount, they fail and reek havoc.

With all this trying and stuff, the spark plug integrity is suspect.

Attachments to follow as an Edit, I need to rest my One Eye for a while.

Questions:
When did it lkast run as designed, and what happened to stop that?
How old are spark plugs?

 

Hi Greg, Thank you for your reply, I have checked the injector loom for resistance on every plug I was getting a resistance of .620 MΩ, continuity is present on the positive side, I checked the harness via a multimeter, holding the - (earth, ground stick) to the battery negative terminal on the car and using the positive stick I checked the positive side of the plug, I can post some videos to show how the injectors work, if that would help.

 

Hi Greg, thanks for the reply, I will look down on the PDF you have sent me, the car was known to run 20-30 years ago, it has 86.000 KM on board, it was purchased from Germany last year by me, they tried to start it but failed miserably, and they basically bombarded it with parts and it didn't work, for example the RPM gauge is from a 6 cylinder unit instead of 12, all earths were checked and cleaned the only one I didn't check was the one you mentioned near the left engine mount, I will take a look tonight and keep you updated. The spark plugs are new, it was the first thing I changed because I was doubtful of the old spark plugs, they were 20-30 years old but they would still work, if you want I can remove a plug from the distributor and send you a video of how the spark looks like when I try to run the engine.

 

Also one thing to mention is that when we try to crank the car the negative cable for the battery terminal get's warm to very hot to being barley able to touch it, the positive cable for the battery terminal does the same thing, but it won't get that hot to the point you cannot touch it, is it normal? I am thinking that it might be normal since it's a huge engine and the starter works hard to turn it.

 

So here are some videos.


you can see here that we have fuel returning
Bank B injection
Bank A injection
injector loom continuity B
injector loom continuity A

I have checked positive continuity as well and it registered ok.

Trying to crank it

 

This is absolutely NOT NORMAL.

You must do all of the following before trying to start the car again:

1. clean to bare metal the engine earth points, engine to subframe, subframe to chassis rail.
2. Remove the carpet on the right hand side of the battery. You will find two ethe points, remove the bolts and clean up the chassis and the earth connectors to bare metal
3. Use new bolts to reinstall all cleaned up earths.

This is awkward to do, but the alternator to starter motor conections must be cleaned, and the connector at the RHS battery connector on the firewall, below the bonnet rear edge. Disconnect the battery while doing this.

 

Hello, we have already did this, they are cleaned and we added cooper washers

 

Some photos to help:










Once cleaned and fitted, protect all the earths with grease, Nickel grease is best. If the existing earth straps look bad, fit new ones!

 

Have you checked the resistance and the continuity in the battery cable between the battery connector and the firewall post and from there to the starter?
Have you tried using another battery. You have a HUGE resistance (or is it a huge semi-short circuit?) in the circuit somewhere which is causing the heat.

 

i have checked the resistance as you have said and it returned to me 0.01M Ω

 

So we cleaned the earth strap to the engine and added cooper washers the engine cranks faster now but the negative terminal still gets hot very hot after cranking it for longer, tried reaching the starter but it’s more complicated aince it has the catalysts on.

one interesting thing there is a surge when we crank with the negative probe on the negative terminal and the positive probe on the engine block.