That's a pain
I was under the impression that there was a calibration that had to be done, which could only be done with a proper Jaguar service computer. There's a lot of conflicting information out there though, and it's hard distinguishing what's for the AJ26 and what's AJ27.

I thought there might also be the possibility that something within the TPS itself might need adjusting? Some kind of 'set to zero' adjustment that could be tweaked?

I'll call the local indy garage, I know they've replaced a couple of throttle bodies recently, so they may know a few tricks.
Either way, I figure it can't hurt to get it checked over by a second set of eyes, before I go through the process of sending it back to ASI for a second rebuild...


I'm actually starting to think that the upgrade to a maxbore unit might be causing more issues than it's worth, and that I could just get my original TB rebuilt by ASI, and then some time in the future I can look at putting the 'new' one in.
The most important thing is to get the car running reliably, modifications are a distant second.