Hi all,
im looking for a little help. can i put a 1994 4.0 in a 1990 xj6.
i need to replace the engine in my 1990 xj6 4.0. (2nd engine, i installed a engine in the car 4 months ago, ran great until a valve dropped in a cylinder, so now i get to do it all again)
question, what is the difference between those years, concerning the engine?
i came across a good (hopefully) 4.0 out of a 1994. looking at the 2 engines i noticed the 1990 has a oil fill tube off the side of the engine.
on the 1994, the oil fill is in the valve cover itself.
is there any other difference ( sensors, wires, etc.) between the 2 different years. anything else need to be changed or modified?
thanks in advance for any help.
Bobby

 

The fuel injectors changed somewhere around 1992 so they must be changed and possibly a few other sensors but that should be easy enough by just swapping the parts from your old engine assuming they're still working correctly.

 

Hi Bobby,

Sorry you're having to swap engines. There are a number of considerations including the fuel injectors 95Leaper mentioned. In '93 the ECM was revised for adaptive fueling and other changes. You might study the AJ6 Engine Management System Guide available at the link below courtesy of our forum member Gus and his jagrepair.com website:

AJ6 Engine Management System/OBDI Diagnostic Guide

You may also find some helpful info in this thread:

https://www.jaguarforums.com/forum/x...l-swap-174644/

Cheers,

Don

 

I don't know if it makes much difference but the late cars use a pair of electric fans and don't have oil coolers.

 

Bobby,

I just thought of another issue you may have to deal with. I think in '93 a higher-output alternator was fitted and it used a wider pulley and drive belt. I'm not sure if the electrical connector(s) were changed - it might be worth getting the '93 engine harness in case you need to swap out any connectors.

Cheers,

Don