We have 89/90 'G' that keeps cutting out. It can go for weeks and runs like a dream, and then has phases were it is constantly cutting out at any speed, high or low. Just before cutting out it sounds like the fuel pump
speeds up.

Have today replaced the fuel pump relay, but it hasn't made a scrap of difference. Can anyway give any advice as we are running on one vehicle at moment, but partner going away next week for 12 weeks so we desparately need the merc running.

Regards