MY 1991 190E 2.6 HAS GOT ME AT A LOSS. A COUPLE OF WEEKS AGO IT STOPS RUNNING. AFTER GETTING SOME ADVICE FROM ANOTHER FORUM MEMBER AND RUNNING A FEW SIMPLE TESTS WE FIGURE OUT THAT MY MAS CONTROL UNIT IS BAD(FUEL PUMP RELAY). I PURCHASE A UNIT AND INSTALL IT AND... STILL WILL NOT START. COULD ANYONE SHED A LITTLE LIGHT AS TO THE NEXT STEP I SHOULD TAKE? ALSO IS THERE ANY WAY TO TEST THE NEW UNIT(MAS CONTROL UNIT) TO SEE IF IT IS BAD? THANKS IN ADVANCE.