Fiat Bravo motor Hämmert 1.6 16v 103 ps Bj 24.09.1997

Hello people have a fiat bravo 1.6 16v with 103 ps the Bj is 97 hope you can help me further so the motor of the hammer has been very strong for some time it will also get worse and worse permanent misfires so it sounds as if he only runs on 3 cylinders he does but not compression was done also nothing everything OK then the timing belt was supposed to have skipped once he is new now and the problem still hasn’t gone away with fiat they told me it kö nnnt a broken camshaft it will always be something new you have also experienced with the motor before I hope you can help me achso would not notice a broken camshaft when changing the timing belt????I thank you for all reply gruss