Hello
Is there anyone that can offer information regarding this project please? We have the XJ40 and are looking for a donor X300 XJR. Are there any major roadblocks to slotting the AJ16 Supercharged into the XJ40?

 

I had considered this too. It seems to simple. You'd need to change the computer and some wiring being that the aj16 is a distributorless motor and it has obd11 codes instead of obd1. i think it depends on your level of determination. I know some people find that side of it easy, but I am not one of them. I think the transmission controls may be different too but I could be wrong there, as Ive not had an 89.

 

Hi ChaseEngines,

Welcome to the Jaguar Forums! It's great to have you with us!

As Jerry mentioned, the very least of your issues will be that the Engine Control Modules for the XJ40 and X300 are completely different. The XJ40 uses a Lucas/Bosch system, while the X300 uses a Lucas/Sagem/GEMS unit. The X300 is Jaguar's first OBDII car, so other modules are also different, including the Transmission Control Module and Instrument Cluster. The wiring harnesses are different with many different types of connectors. The braking systems are different: the XJ40 has hydraulic power assist while the X300 has conventional vacuum power assist. Off the top of my head, I seem to recall that the steering rack on the X300 is a ZF Servotronic variable-assist unit that requires a vehicle speed signal from the ECM or TCM whereas the XJ40 rack is non-variable-assist. The locations of fuse boxes and power distribution are very different, so extensive re-wiring might be necessary.

Here are some resources that will help you compare the cars and parts:

Jaguar Land Rover Classic Parts

Jaguar XJ40 Electrical Guide 1987-1989

Jaguar X300 Electrical Guide 1996

Cheers,

Don