Cadillac Repair: 1998 CADILLAC SEVILLE STS, cadillac seville sts, mass air flow meter

Question
WHEN I FIRST START UP ENGINE IT WILL RUN RUFF AND HAVE CYLINDERS MISFIRE UNTIL NORMAL RUNNING TEMPERATURE IS REACHED. THERE SEAMS TO BE NO POWER LOSS WHEN DRIVING.THE VEHICLE HAS 70,000 MILES I TRY A TUNE UP PLUGS WIRES, FILTERS AND FUEL INJECTION CLEANER. AFTER THIS DID NOT HELP THE PROBLEM I HAD THE FUEL INJECTORS CHECKED AND CLEAN AND FOUND THE THEY WERE NOT WORK AT 100%. I REPLACE ALL EIGHT INJECTORS AND I STILL HAVE A PROBLEM. CAN THE MASS AIR FLOW METER CAUSE THIS PROBLEM WHEN COLD AIR FIRST ENTERS ENGINE INTAKE?  IF SO? HOW CAN I CHECK THIS OUT WITH OUT BUYING A NEW METER TO USE FOR TESTING. I THINK IT IS AN ELECTRON PROBLEM RATHER THEN A FUEL PROBLEM.

CAN YOU HELP?
THANK YOU  

Answer
IS or HAS the CHECK ENGINE light ever illuminated while driving the vehicle and or has any other lights illuminated or any messages from the message display center ?.

What work or diagnostics of ANYKIND WHAT-SO-EVER have been performed on the vehicle trying to fix this problem ?.