Hi back to my unsolved problem! ( Omega stuck in limp mode runs at only 1200rpm, no throtttle response)
I've now had a measure of the throttle body using ohm meter. It has two pots, they read ok according to my Autodata manual. The servo motor resistance reads low (2.4ohm not 3.

, The butterfly valve seems a bit jerky when I gently push it.
Status
1 \Breathers cleaned ( no problem seen)
2 Throttle body cleaned (small hole blocked , now unblocked)
3 ECU code reports ETS problem (Electronic throttle system)
4 I've not checked the signals from the throttle pedal which is candidate but it has two pots that would need to fail so I'm not convinced it could be that but I am going to do next if I can find the connections.....
I've researched a bit ETS. There are several limp modes for this if it detects a failure.
http://www.autospeed.com/cms/A_108379/article.html this is a very good link for Bosch Motronic ETS and I appear to be seeing Emegency mode three which cuts off the throttle body and limits the engine to 1200rpm if it gets confusing inputs from the throttle body.
So unless anyone has better advice (!) I'm going to buy a second hand throttle body and try that, and check out the pots on the throttle pedal while I wait for it.
If I bought an ECU reader what type would I need ( I have a laptop)
Vincedomingo