'91 Buick Skylark GS,3.3L

Engine starts & stops immediately. Sometimes will run for 5 seconds to a few minutes & dies. Fuel pump/filter new,pressure checks perfect. TPS new. BRAND NEW plugs/wires. Condition started abruptly,overnight.

Check to see if the TPS connector came loose, or got water in it.

The problem might be with the ignition module.

Ignition modules function in two modes. These are the start and the run modes. When starting the engine the module allows full battery voltage to the ignition system to ensure the cold engine starts when the fuel mixture is rich. Once the engine starts and the ignition switch moves to the run position, the ignition module switches to the run mode. The module then steps the voltage down to the ignition system so things like the coil and plug wires don’t burn up from the higher voltage the charging system is delivering to the battery. This was done with a ballast wire or resistor on older ignition systems but now the ignition module performs this job.

So it could be that the start mode of the ignition module is functioning, but the run mode of the module is failing.