Gravenor

Hoping for some suggestions here! Quick precis of the situation.
2008 40th Anniversary model, owned from new lovely car - usually

Exhaust blew. Put up on ramps but didn't deal with this for 4 months or so and as the car sat up there the battery charge dropped to the point the alarms tripped and the centralized locking didn't work.
So I decided to change the exhaust and when I went back into the workshop there was evidence of an oil leak.
SO
Drained the oil, changed out the failed oil cooler line, changed the oil filter, recharged the oil.
As it was on the ramps, drained out and changed the gearbox oil, drained out and changed the diff oil.

Changed the blown back box and the next 2 sections of exhausts including the CAT

Charged the battery

Put back together and started the engine ran for 5 seconds and as the revs started to drop, touched the throttle and there was no response, engine stalled.
Cleared the chambers and restarted exactly the same sequence of events.

Assuming I had tripped something while changing the cat sensor I connected a code reader to the car and this was a TPS error code. reset a couple of times and instantly re-signaled the same error.

I popped the air intake hose to see if the butterfly was free which it was but this valve did not respond at all to the throttle action.

Any ideas where to start with this one?

Thank you