So I took the loom for a bank off and went over it wire by wire.

I did find one error but after the adjustment I still get the same results on all connectors in that loom. 12v one pin .1v other pin.

Here is a picture of my wiring.


remember B bank is 12v both pins.

I'm stumped and calling it a night

 

So I hooked up the a bank injector loom back to the injectors, but not the the main connector. Turned car on, touched the wires expecting to here the injectors click... nothing... I turn the capscan and b bank clicks. Hmmm. I try again... nothing... Turned off car. Looked around the engine. Go over to ignition amplifier looking at the wires / ground wire etc. Where the ground cable goes I'm like I think that grounds probably not good. I remove the one mounting bolt. I had painted the box. So where the ground goes I sanded to bare metal. Reconnect ground ring. Call wife. She's tired I'm tired but she know I won't sleep unless I figure something out. the a bank injector loom is still connected to the injectors. I pull a random one.... 2A i tell the wife to hold the meter probe to one of the pins while i touch the wires to the main harness. 12v. Ok i tell her to go to the other pin. 12v. I'm like wtf. So turn car off. Secure all wires to the main harness. I test 6A both pins 12v. I got to 5A same I continue and all are 12v both pins. Last one plugged in is 1A. I remove it from the injector. 12v one pin. .1v other pin. WTF I yell. I test the others. All back to 12v and .1v 2x WTF I connect 1A back to injector thinking something crazy. I test 2A. Both pins 12v. 3 x WTF I test the rest. Back to 12v both pins. I disconnect 1A and connect a random 4A. Test 1A. Both pins have 12v. 4 x WTF conclusion. at least one injector has to be connected for the whole bank to have 12v each pin. When I firsted test this morning I already knew in b bank 1B was ok so I left it connected and disconnected all the other connectors. That's why all of b bank still tested 12v both pins. Or maybe it was that ground cable not properly grounded to the amplifier box. So I'll try tomorrow (kids asleep now) to see if it will start. I also tested each injector one at a time and could feel each one click when I turned the capstan manual. Wife worked the ignition on/off for me. More to follow tomorrow.

 

Day 3. Efi harness is good.

I cleaned some more grounding points I found.

Link to where i am still at.

 

Start a new thread... This thread is a "STICKY"... Not exactly the same as a general discussion area... Jus say'n

 

I'll just add. Sounds like you might have your firing order mixed up,,, coil wires reversed, or both. Maybe?

I say that because you can hear the engine is really struggling to roll over. Should be spinning even without spark or gas, faster and smoother than that. Easier, if you know what I mean...?

 

I'm awake, and still considered "active", as in crutches now keep me vertical.

Injectors ALL connected, and Ign in the ON position, 12V on all 24 pins is what is needed, or the beast be dead.

That EFI wiring is as simple as Noah's Arc.

5 wires.

ONE is 12V Ign active.
The other 4 are the trigger wires for the Injectors which are grouped in 4 lots of 3.
1,3,5A
2,4,6A
1,3,5B
2,4 6B.

A = RH side sitting in the drivers seat facing the front of the car.
B = LH side, ditto.

I DO NOT speak Drivers/Passenger slang.

The Resistor Pack (Power Pack in some lingo's), is located IN the engine bay, aft of the RH headlamp housing, and has a multi-pin plug in from the bottom. That plug and socket need to separated and CLEANED (Lemon Juice with a WD 40 rinse) TWICE. That is now the weakest point on these aging systems. Followed soooo close by the loom itself internally doing obscene things between wires.

Yours is known as a Marelli car, meaning the Ignition system is Marelli as versus the simpler Lucas system.

I know NOTHING of that system, only seen 2 of these cars down here, never got involved in either of them. All teh Marelli stuff is well documented in teh XJS archives and easily found.

The EFI system is the same from 1982 to 1993ish. Known as the P Digital system.

 

Ill check those today. Thanks. Also bought a can of starter fluid to see if she'll catch.

 

Starter fluid didn't work.

I checked all the plugs they are in the right order.

 

If the starter fluid failed, you got no spark to make it go bang.

That list could be long, but the basics.

12v at the White wire on the coil, REMAINS 12v while cranking. Ignition switch electrical section is getting near #1 on that list.
The Condensor thingy INSIDE the Ign Amp is removed. They leak to earth, age related, and are redundant anyways.
The carbon brush contact inside the dizzy cap is still there, they fall out.
The small lead, Amp to Dizzy is in GOOD shape internay. OHM test the thing, wiggle it around, watch the meter. That lead is also nearing the top of lists, age related, and the fact it gets caned a tad when changing sparkers.

 

If you go down to my build thread you will see videos I posted. All leads etc sre brand new. I bought a noid kit today but im talking a day off from trying.

The condensor thing i have removed but will tomorrow.

I did test the coil 12v while cranking. It dropped .5v only which is within 1v acceptance as stated in your how to.

New csp and rotor as well.

I know it's something simple. Always is.

 

Good news. It started after I did some more things. Check out my build thread for info.

Very excited to get it running properly now.

 

The best authoritative narrative on how to solve a no start situation for the Jaguar V12 engine