I think I fixed my problem today ! I changed the spark plug wires and everything seems back to normal ! My car wa so slow that I think it was running on only 3 cyl. !
I will also change the fuel filter and clean the MAF soon.
I'll give you feedback when it will be done.

1999 CSVT - 104000kms, Black/tan RU-3530, 17" Rage Enduro, Hella Optilux fogs BAT kit on its way ! 1997 Contour gl sport Zetec mtx SVT Shocks and Struts No resonator SPEC stage 1 clutch