I have a 2001 xkr coupe, and have a problem with the engine wiring harness. All of the insulation on the passenger side coil wires have lost their insulation (it went brittle, and looks to have just cracked off) and now the wires are all shorting out on each other.

Here is my question, I want to replace the engine wiring harness, is the 4.0 s/c harness on the xk the same as the 4.0 s/c from the xj? Also, is it the same as the non supercharged 4.0 from either model?

Thanks,

Ben.

 

The harnesses are not the same as the normally aspirated because they have VVT solenoids/actuators. I think the 2000MY onward 4.0 XJR/XKR AJ27 harnesses are the same (part #AJ82931)

bob gauff

 

If the connectors are still intact, you might want to consider reinsulating the coil wires with heat shrink tubing or tape. You can cut and solder splice to insert the tubing, or use adhesive lined heat shrink tape without cutting and spicing.

Adhesive lined Heat Shrink Tape : Heat Shrink Sleeving : BuyHeatShrink.com : Heat Shrink Tube

 

BTW, this problem is likely an indication that you have had leaking spark plug valve cover seals for quite some time and the hot oil residue has destroyed the insulation...this needs to be corrected.

 

Thanks for the help. Ijust bought this car cheap as it wasnt running right, i initially thought that it had jumped a tooth, but the cam flats are all aligned, although the tensioners are plastic, but they will be getting replaced as i have it all open.

It has 190,000 on the clock so all of the wires are pretty brittle, i figure this is the most likely cause of the rough running, i have also had a scope into the cylinders, and all looks good in there too.

I did also notice some oil down in the spark plug holes, so was going to replace the plug cover seals anyway. Where is the cheapest place to get all of these gaskets?

I would like to replace the harness if i can, all of the wires at this age are starting to get brittle because of the mileage, hopefully this will take care of any issues down the road in relation to this.

I will look for a harness from a 2000 - 2003 XJR because i think that there are more parts around for them than the XK.

Ben.

 

A good quality, fully compatible and complete gasket set (valve cover, full set of grommets, spark plug seals) is Felpro (Part # VS50724R) at a great price ($37.09 last I checked) from Rockauto. http://www.rockauto.com/catalog/x,ca...parttype,10710

Also,these are chaper Ford equivalents for the tensioners in case you have not bought them yet. You also need the new bolts..thry are a different length.

Ford PN 2W9Z6K254BA Right Secondary metal bodied Tensioner (1 required)
Ford PN 2W9Z6K254CA Left Secondary metal bodied Tensioner (1 required)
Ford PN W500301S300 Bolt (4 required)

I got good pricing at http://www.sunroadfordparts.com. The Ford parts even said 'JAG' on the box.

 

I had a similar issues on a 1998 xk8 4ltr and the ignition pack plug connectors had totally disintegrated. I bought a complete engine loom in good condition from a breaker for £30.00 and he included all of the injectors. Took an evening to clean and test and tidy one or 2 loose bits of outer insulation and a long evening to remove the old and install the replacement. Would recommend it as it solved an ongoing intermittent misfire. I cleaned all the replacement connections with contact cleaner and an airline then applied a sparing amount of 3 in 1 silicone spray to the internal rubber seals.