I bought this XK8 with numerous engine codes. Needless to say it was running poorly. At the advice of one of the forum members I sent my ECU to ASI for testing. The unit was found unrepairable. I bought a new one and installed it but the codes were still there and the car still ran terrible. I started checking the fuses and the 10 amp fuse for the throttle body motor came out too easily. Checking the fuse diagram I found the fuse was one spot off and in a blank space. Looking in another fuse box I pulled the 10 amp fuse for the transmission control module. The fuse came out but the blade on one side stayed in the socket. I replaced that fuse and now the car runs just fine. The previous owner had told me that the car was just returned from a shop who replaced the transmission. A skeptic might conclude that the fuse problems may have been man made mistakes on purpose. I'll never know for sure but the previous owner gave up on the car and sold it to me for an embarrassingly low price because he didn't want to "spend another dime" on it. Sabotage or stupidity, you decide.

 

Hopefully the tensioners were done by the time you got it. If not, all of the chains, guides and tensioners need replaced.
Also, pull the lower oil pan and look inside the oil pickup for any broken plastic guides. All of this is necessary and piece of mind.

 

I suppose the ECU is used. Did you check the interior for capacitors leaking? If so, you must repair it fast..

 

"never ascribe to malice what can be attributed to incompetence"