OK....so it's not the plugs or the coil. Spitting and sputtering sounds electrical. These computer controlled engines can be extremely hard to diagnose. You might try replacing the distributor cap and rotor. A small crack can cause some very significant spitting and sputtering. After that it's time to put it on an engine analyzer.
Not in the vacuum line.
The vacuum modulator is located on the passenger side of the transmission, just above the tranny oil pan. It has a vacuum line going to it. It actuates a valve in the tranny for upshifts.
a vacum works with the tranny to Shift an automatic vehicle
ontop of the tranny
i suggest you either adjust the bands or get a new transmission.
could be a vacuum leak, or throttle positioning sensor
NO. That year transmission is electronic controlled. NO vacuum source needed.
It does not have one.
The transistor replaced the vacuum tube, allowing radios to get much smaller and portable.
Perhaps a vacuum leak either under hood or under dash Perhaps vacuum booster unit check valve defective
Chech ALL vacuum hoses. The tranny shifts by monitoring vacuum pressure.
Vacuum tubes were first replaced by transistors, and later by integrated circuits.