Sputters under acceleration..evrything electrical to fuel has been checked.

yes

It could be an ignition problem, or low fuel pressure.
If the spark plugs and ignition system are in good condition, I would check fuel pressure and the filter.
If the throttle position sensor is failing, the check engine light should be on.

If the check engine light is on you should have the computer scanned for trouble codes. The codes will direct you or a mechanic on where to look for the problem.
Sometimes the problem is low fuel pressure or a dirty fuel filter.

spark plugs dist cap spark plug wires

Hi Missippirebe, I think you should replace the fuel filter and if the problem persists check fuel pump pressure. It should be at around 3.7 bar. Regards John

IF I UNDERSTAND YOU RIGHT YOU ARE HAVING A MISFIRE ISSUE UNDER LOAD MOST COMMON FIX IS PLUG WIRES. CHECK VEH FOR BASIC TUNE UP FUEL FILTER PLUGS WIRES FUEL INJECTION CLEANING

How many miles on car? It could be fuel pump and or alernator or both.

Replace the fuel filter.

CHECK THE FUEL FILTER FIRST.IF THE FILTER IS PLUGGED U CAN HAVE THE SAME PROBLEM.IF THAT DOES NOT FIX IT U NEED TO CHECK THE FUEL PRESSURE.THERE IS A FUEL PRESSURE TEST PORT ON THE FUEL INJECTION RAIL(TOP OF THE ENGINE)THE PRESSURE SHOULD BE 40-47PSI.KEY ON ENGINE OFF.

It sounds like you may have a problem feeding the fuel to your engine, I had the same problem with my 89 RS. All the 1989 model's fuel systems were recalled. I think you may need a new fuel pump. The fuel pump is located inside the gas tank in the rear of the car right under the rear axle. The fuel pump itself isn't too expensive, but with other small parts such as the electrical harness upgrade and fuel filter and the labor you should be looking somewhere in the $500 range. I hope this helps.