What he said.
Likely culprits providing it makes it to top gear.
Coil, resistor tip, plug, wire, MAS, vacuum leak or wiring harness.
If it "sticks" in second or third.
Speed sensors in conductor plate, rear abs wheel speed sensor, wiring harness, shifter posistion switch or atm leakage into the atm connector "wicking" trans oil into the etc.6 control unit.
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.