Okay,

Apparently the 5.3 facelift has a 6-pin connector instead of 8 so the wiring diagrams I've seen don't apply to this one. I spent the afternoon with a tester and some paper and as soon as I get it drawn out I'll post a diagram for this car. Effectively, it's the same as the other diagrams with 1 common ground for each bank.

My next task is to trace the coil wires so I can replace those as well.

 

would like to see those

 

Well, I've emptied the V. What a mess! I've found several spare parts and an acorn will post pictures of everything but here's the V. I highly recommend removing everything in your line of sight if you do this project since it's too emotionally challenging otherwise. The question to the group is... do you want to see my drawings of the wiring or do you want to wait for my dad to do the AutoCAD drawing?

 

Stuff some rag or paper into those injector holes, or danger and grief lurks! Good luck with the project!
Greg

 

"... do you want to see my drawings of the wiring or do you want to wait for my dad to do the AutoCAD drawing? "

Both!

 

As with all small jobs this one's become rather big! I knew it would but hoped not this big

I've finished tracing the wires... for the most part. This facelift 5.3 is kind of a bugger as wiring goes. Every important sensor for the top end of this motor runs through the v. The ignition module loom runs from the front of the car, weaves through the bolts on the valve covers to the rear where they circle back into the wiring mess at bottom of the v. Everything ultimately either terminates at sensors or snakes trough the v and up the firewall on the A side.

I've gone from rewiring the injectors to now doing the whole darn car. Oh well, at least I will have good wires throughout when I'm done. My biggest anxiety now is finding all the connectors and wire colors I'm going to need.

 

Whole darn car? I hope you are just joking. Or I am missing some history?

Unless the car has been in a fire or a flood I'm sure you'll find tha 95% of the wiring is 'good wires throughout' already.

Engine bay wires suffer from heat as we know. You're on top of that. Some connectors suffer from water/weather exposure but those can be singled out and repaired/replaced as needed.

Years ago I bought an *entire* wiring harness from an XJ6 for $75, including shipping. Almost every foot of it was in pristine condition. I'm still using it for projects and repairs.


Cheers
DD

 

Well, the answer to that is maybe some wires are good and some wires are not. I know for a fact that all the injector, ignition and sensor wires in the V are toast because I can see this with my eyes. No fires, just dried out and cracking insulation. Whenever I touch any wire that is in contact with the engine I hear the Rice Krispies guys singing to me.

My plan is to replace every single wire that is running through the v and the ones that are running through the valve covers... since they are the ignition module and coil wires The answer to that is effectively yes, I don't want to do this again.

The good news here is that since I've yet to find a schematic and have to painstakingly produce one for this 18 months long car model (1992.5 - 1993, 5.3), a few people will benefit from my attempt. The only thing I can say is please be patient since my scribblings will have to be refined for others to follow

 

shouldn't the diagram be the same for the next cars then? the 1992 diagram shows a 6 pin with 2 grounds

 

Thanks for posting this sidescrollin. I will have to study it more but I can tell you that the car isn't wired this way. Here is my ameture drawing of what's actually there on A bank (B is exactly the same with different colors) and you can see the difference.

 

Good luck with your project. On my 78 I also found all the wiring in the V to be nasty. I fabricated a new injector harness, reconditioned the distributor. The rest of the wiring in the car seems to be generally OK.

 

yes they are

if you look at the injector bank ( top 6 lets say ) the wire on the right goes to all six ( as per your drawing,

the two wires on the left go to two banks of three injectors, ( again, as per your drawing )

the Jaguar drawing shows connection points as well ( black termination points ) as well as plug connectors

wire for wire, the two drawings are the same

i have rewired my injectors for a Marelli car some weeks back

the thread is here , just for some support, as its not a simple task

https://www.jaguarforums.com/forum/x...ctures-127573/
BB

 

thanks BB, I read and reread your post before I even turned the first bolt on this and it was helpful and gave me the fuel I needed to jump in.

Okay, here's where my novice comes in so please be patient with me.

The Jaguar drawing shows the injectors and wire colors grouping like this on A:

Orange & Blue- 1,2,3
Orange & White- 4,5,6
Pink & Black- 1,2,3,4,5,6

My Car is like this on A:

Orange & Blue- 1,3,5
Orange & White- 2,4,6
Pink & Black- 1,2,3,4,5,6

Essentially my care is like yours except that mine is 6 pins and yours is 8. I'm not an expert at reading wiring diagrams but I'm having a hard time trusting that this Jaguar drawing is the same as my car? What am I missing? I'm not sure but believe that if I wired my injectors like the Jaguar drawing my car wouldn't run.

 

the thing to take hold of is that all 12 injectors have a common feed as they are all always live
( so thats two wires that can be made to one ? ) with the ignition on.

then there are four switching circuits to ground through the power resistor and then ECU
2 for the A bank ( odd number injectors and even numbers ) ,
2 for the B bank ( odd number injectors and even numbers )

after that you can mess around with how the physical wires are routed and grouped

if you look carefully at my main loom plug ( i know its different to yours ) you will see all the pink wires joined together on the ' live ' side of the plug, then have separate feeds out to each bank ,


If you follow the two KB wires back to the main FI relay they got to the same pin, so they are the same.....

so in theory , you can get away with a 5 pin plug as a minimum for the 12 injectors..



BB

 

Hey Sidescrollin, any chance you have the ignition system diagram for this car too? I've nearly pulled all the wires and as I suspected... everything that came in contact with the block is fried.

I'd say that 96% or all the wires are bad

 

sure thing man.

 

Thanks Sidescrollin!!!

Can anyone tell me where this loom terminates after it goes through the boot? I pulled the boot back and can't see anything down there and not crazy about pulling the plate with all that brake line attached to it. This is the EFI,ignition and associated sensors grouping as it goes to the computer. I'm wondering if it comes through into the cabin directly to the ECU or if it terminates to a connector on the firewall?

This is the last connection for that whole mess of loom that I need to liberate the entire harness.

 

You know the colors you are looking for right?
I would try popping the passenger side cover under the glove box and see if you can locate them. There is a chance that there is a connector for it there, since there is a panel with fuses, relays, and other stuff. Hopefully it plugs in around there and you don't have to wrestle it out.

Unfortunately the only harness routing I can find makes it seem like the harness is just continuous so you understand the routing, it doesn't indicate where or if there are any plugs separating the harness into pieces.

okay, yeah, you will have to look for them but it doesn't seem to be continuous, given this pic I found of a straight 6 harness

 

thanks again sidescrollin

This has proven to be most helpful. I hope I don't offend anyone by saying that reading these diagrams is kind of like watching old man **** I'm fascinated and kind of scared but I just can't put it down. I'd love to get all the diagrams for my car. Is there somewhere I can get them? I'd love to pay someone for the entire book.

 

The answer to your question of where the harness goes in the picture you posted, is to the right front, behind the kick panel. Its kinda tricky though. When you take those 4 bolts out of the plate that harness runs through, you will find a vacuum reservoir. What you are doing is very "doable", just takes lots of time, patience. I am sure you realize by now that there are several coax cables in there? And you must use coax going back, due to the frequency put off by the front and rear " sensors", which are really small AC generators (magnetos?)