If it sparks and theres fuel .. then go out from the worst scenario Erico .
Things can only go better seen from off there .
Worst case would be a bearing problem , wich causes air pressure leakage through the crankseals .. its got about that amount of miles on the clock to seriously consider this scenario. Its some work but not the most costly thing to fix . If you feel any movement on the crankshaft , especially from the ignition (right) side think you can conclude thats the original error the previous owner decided on to sell it .
air injectors can be broken , but in practice havent had one wich really was .. mosttimes it was the crankbearing/seals combi ...second best was a worn out air compressor ..concentric wheel is kind of a teflon wheel rolling over the fully rounded cracksides thus picking up the motion for pumping its air ...
Another trick of one of our members did was he tried to connect the air hose directly to a external compressor and applied the air this way .. started and ran fine wich told him the compressor was worn out .
TSDI's are a bummer to get experienced with , but once you can fully understand its achillesheel and can tackle these inconveniences it becomes a very rewarding scoot . Its knowledge many pro-dealers get grey hairs from because of its complexity ..being able to hme fix it will shurely lead to admirance from many