i bought my wife a 99 tdi, and it will ocassionally shut down.I am loosing power to the number 29 fuse intermitantly which is going to the ecm and which in turns cuts off the the power to the fuel shut down valve on the pump.does any one know what powers this fuse? its only hot in the start or run position so its not comming from the batt. does this have a relay to energise it? if so which one? has anyone else had this problem?

power supply relay

Theres 2 relays under the dash, they are #52, one is yellowish/white and one is black (glow plug relay) replace those, there a common problem. Or just go the the vw dealer and tell them you want the "glow plug relay" and "power supply relay" for tdi

thanks, ill try that. traced the wiring out in a Haynes book and it kinda pointed to the power supply relay. funny thing was when i turned the key to the on position and if the glow plug indicator light didnt come on all it would do was spin over. if the light came on i knew it was gonna start. thanks for the info...