fiat bravo 1.4 Bj.96 does not jump on when engine warm

Hi.. so my fiat bravo 1.4er Bj.96 (whos need KBA:4001-082) doesn’t jump on when the engine is warm but as soon as the engine is completely cooled down after approx.3 sts. again he jumps wonderfully and also during the ride no breakers or jerks. so I called now at fiat and they said to 90% crankwave sensor now the question is this part and 2. question where do I find the one at the engine block?I also read that there is still camwave sensor and so on! MfG thoma s