Ford Galaxy tdi weird problems

[CJDav56]

My 2001 Ford Galaxy 1.9 tdi which I recently bought was lacking power, the speedo was not working, fuel gauge fluctuating and the Glow plug light flashing. On checking the fuse box I saw that fuse 34 engine management was removed. I replaced this fuse and the car started running well with speedo working, fuel gauge working normally and no glow plug light flashing. However after a mile or so it lost power and when I went to turn ignition off, the engine carried on running even with key removed. I pulled out the 34 fuse and the engine stopped, replaced it and restarted, with the same story, good power for a while then low power and engine not turning off until fuse removed. A friend connected up a portable error code meter but nothing was shown. Has anyone any ideas what this could be caused by? Thanks in advance for any replies.

[CJDav56]

Thanks for the replies and sorry not got back sooner. The problems have now been sorted, two seperate issues. A previous owner had wired something direct from ignition switch and when this wire was disconnected the ignition worked fine, re switching engine off. All electrics are working ok so don't know what this was supplying. The power and limp mode issue was caused by a split in the pipe from boost control valve to turbo.