Hi i'm Elias i had the same problem on my disco 2 2003 ,start by the fuse n14 inside the car driver side,after that it might be the cps crank position sensor ,at the end check your coil ( hard to access)these are all the answers i had when i posted my problem here ,believe me i did replace all those parts and yet didnt fix the problem ,cause mine was electric the wires were getting on fire (passenger side behind the gloves box melting wires causing the problem good luck.