I have a 2003 XJ8 NA. Looking at a salvage not rebuildable title 1998 XJR. Read through posts on compatibility problems between the years. If I swap everthing including ECU does this solve compatibility issues?

 

NO!

Easier to just go with 'like-to-like'.

If you park BOTH cars 'side-by-side' and swap EVERYTHING that is different between the cars you could probably succeed.
That would INCLUDE wiring harnesses as well as all the mechanical and electronic parts!!!!!!!!!!!!

good luck

 

I second this, people don't think about it enough. Having had an electrical issue on my XJR recently I had a thorough look at the electrical guide and you wouldn't believe all the little differences between the N/A and S/C models in the wiring.

 

Thanks for the input. In my FFR build, I put in a ‘99 Cobra engine. The ECU and wiring harnesses controlling engine, tranny, fuel were completely separate from the body control units and wiring. Are they separate on the Jags?

 

Look at the electrical guide and you will see that the CAN bus INCLUDES the ABS system.(CHASSIS)

The CAN bus wants to have vehicle speed info.

 

Thanks for the advice. Have been fixing up this $1900 purchase. Getting new headliner today. If I can find a hood to replace mine that is loosing clear coat and the boot lid that has a long dent across the back, I think I’ll have a $5000 car. Better plan might be to sell and put money towards XJR.

 

Yes, if it was to build a custom vehicle that doesn't already exist maybe it would be worth it. But considering what an XJR seems to be worth in the US you'd be better off just buying one that's registered and drives.