Driving on the highway up a long incline when the car suddenly lost power and then died. I coasted to the side of the road and opened the hood.

I docovered that the insulation on the brand new fuel injector harness I purchased from SNG Barratt had melted away and some of the wires had shorted out.

The section that burned up was between the ECU and the fuel rail, not in Death Valley. See photos below.







Anyone have a problem like this before or have any idea what the root cause could be?

 

Yikes!

Keep peeling back the tape and sheathing; you might find ground zero. My first though is a "dead short"; 12v positive coming in direct contact with ground....somehow.

Cheers
DD

 

OOPS also.

Never seen that on an EFI loom.

A dead short for sure.

 

How long ago was this purchased thats ridiculous, could of lit the whole car up.

 

Obviously a faulty loom.

 

thats not good at all,

could be several reasons for this,

first (and probably most likely ) the loom as mentioned above, has been bad from the start, so i would not take it apart any further but demand SNG take it back and give you a tested replacement , or you will go viral on the internet about it

or

there is an issue where this has been effected by a component further down the line causing an overload,
basic principle is, injectors are always live with the ignition on, they then go to a ' power module ' which regulates the power for the bank of injectors that are firing ( they are not sequential ) at least in my 1989 car anyway , then this regulated power is controlled via the ECU and switched to ground, this completes the circuit and fires the injector bank for that cycle,



i had to build a bespoke loom myself about six years ago now, quite involved and technical for what it is,




BB

 

Sorry no help here except how f#cked..., you have done the right thing getting a new loom and it ends this way.
I would be very upset, actually that is an understatement.

As stated by brake buster...........

If there is an issue where this has been effected by a component further down the line causing an overload,
basic principle is, injectors are always live with the ignition on, they then go to a ' power module ' which regulates the power for the bank of injectors that are firing ( they are not sequential ) at least in my 1989 car anyway , then this regulated power is controlled via the ECU and switched to ground, this completes the circuit and fires the injector bank for that cycle,

If a short down stream caused this there would be evidence? surly there would be other melted bits?

 

yup....


injectors could be toast, and so could the injector ECU and or the power module, i would be getting it checked before any other loom is plugged in , as it may do the same thing

if its the fault of the 'new ' loom , then you will have a claim against SNG for the whole repair , possibly

BB

 

I contacted SNG Barratt and sent them the photos. They said they’ve never seen anything like this and would contact their supplier who makes the harness and get back to me in 48 hours.

I’ve now had a chance to look over the engine in more detail and take more photos.

One end of the fuel injector harness has a plastic connector that plugs in to the harness from the power resistor. There are 8 separate wires emerging from this harness that get bundled together with wrapping about 3 inches from the connector. All of the insulation on one of these wires (in the lower right corner of the photo below) has completely burned away and all that remains is a brittle portion of bare wire. And the plastic connector for this wire is partially melted.







From there moving towards the injectors, there are several sections where the insulation has burned away and there are fragments of presumably the same bare wire visible.




There is a bit of wire insulation residue on the end of the air conditioning hose. Unclear if this is where the short started (ie, poorly wrapped wire making contact with the metal band) or if this is just collateral damage.



All of the burned insulation is on the main trunk line of the harness before it branches off to the individual injectors. All of the sections leading to each injector look intact.



There is no externally apparent damage around any of the injector connections themselves.




There is no singeing or apparent damage around either the power resistor or the ECU. I have not removed or dissembled either of them as I am waiting to hear back from SNG first.






SNG does not have any more harnesses in stock, so it looks like the car will be out of commission for a while, whichever is frustrating now that summer has arrived. What’s even more aggravating is that I replaced the harness as part of preventive maintenance to avoid this sort of thing happening in the first place.

Any potential explantions of what might have caused this would be greatly appreciated. As well any leads on where I can source a replacement harness.

Thanks...

 

JaguarSpecialties does wiring I have a few from them, including an injector harness looks like new OEM with stock plugs but with better gauge wiring and insulation wrap.

 

Any chance it could have been abraded by a belt? It looks routed differently than stock for sure, I guess to get it out of the vee? As for where to get a replacement, I built my own..no idea how else. What a nasty turn of events, sorry for your trouble.

 

I don’t believe it could have come in contact with a belt. There was quite a bit of distance between the harness and the AC belt shown in one of the photos. I routed it up top to keep the harness out of the Vee.

 

Where does the burnt wiring stop? I would suspect a short to ground at that point. It does not take much. Any slight rub through could do it.

 

It’s burned right up the plastic connector at one end, and between the 2A and 3A injectors at the other end (circled in red below). Not everything in between is burned away, just certain sections.

 

I reckon a new harness will plug in fine and the car will go no bother. This looks to me like a dead short from the loom between the plug and the part where it branches out to the injectors. I would be very surprised if the injectors or anything else damaged.
It would be worth looking inside the power resistor, it unscrews from the body and the side panels unscrew. Inside there are no moving parts, just resistor circuit things (as far as I can tell anyway). Unless it looks scorched and burned it should be fine.
If it does look burned, then replace it with a second hand one, loads on ebay, but you must get the same ID number as on the one you take off, there are others for 6 cylinder cars that look identical but are not. If the resistor does not resist, the injectors will burn out, so it is important to check.
here is a link which has a photo showing the serial number:
https://www.jaguarforums.com/forum/x...sistor-134745/

 

It's been 10 days since I reported the issue with the fuel injector harness I purchased from them to @SNG Barratt USA and there has been no progress whatsoever. SNG Barratt says they cannot refund my money until they determine whether their supplier will agree to reimburse them. And they cannot get any response because their supplier has been on COVID lockdown, only recently partially reopened and have a large backlog of work and a reduced staff. I have reminded SNG Barratt several times that they sold the part to me, they warranted the part, and that their financial relationship with their supplier is none of my concern. In response, I get nothing but vague promises to redouble their efforts to talk to their supplier.

I am quite frankly amazed that a company whose business consists of selling replacement parts at very high margins would hesitate to issue a refund to secure the loyalty of their customer base.

 

Presuming you paid for the loom with a credit card; lodge a complaint with them and they will take up the issue with SNG Barratt. At a minimum they will give you a temporary credit on your account until the issue is resolved. Good luck!!!

 

Under UK law (I know you are in the USA) the contract is between you and SNG, and their relationships with their supply chain, or staff, or anything else, is outside the contract between you and them and so entirely irrelevant to their contractual liability to you. I am pretty sure that USA law is pretty much the same in this area. If you did buy by credit card, the above advice is sensible.
I am pretty sure that you are stuck communicating to someone who is (a) unaware of this and (b) insufficiently senior to realise this stalling is also idiotic in business terms.
SNG are a pretty decent company overall, headquartered in England, and very keen on helping Jaguar owners; it also sponsors loads of Jaguar related things.
I would drop a registered letter to "The Chief Executive" of SNG USA, copy it to the same in the UK, setting out the problem and asking them to sort out the matter. Enclose decent photos etc etc and write "more in sorrow than in anger". They will sort it out I am quite sure.

 

My money is in something with the installation. I do not know who installed your harness or if you did it yourself but my experience with stuff like this is usually human error.
next would be a harness defect but not as likely in my experience.

 

I am at that place with our xjs. I am working on re-installing intakes and after re-habilitating the injectors I am considering building my own harness. Its purely a cost issue. I would absolutely prefer the "just get another one" option but if after some $400 this is the result then whats the diff if I build my own and have the same result. Please keep us posted.