Have you done the reference voltage checks out of the PCM?
How bout the coil?
It may be worth your time to do a stall check.
STALL TEST PROCEDURE
(1) Connect tachometer to engine. Position tachometer
so it can be viewed from driverís seat.
(2) Drive vehicle to bring transmission fluid up to
normal operating temperature. Vehicle can be driven
on road or on chassis dynamometer, if available.
(3) Check transmission fluid level. Add fluid if necessary.
(4) Block front wheels.
(5) Fully apply service and parking brakes.
(FSM doesnt tell you this... put it in drive)
(6) Open throttle completely and record maximum
engine speed registered on tachometer. It takes 4-10
seconds to reach max rpm. Once max rpm has
been achieved, do not hold wide open throttle
for more than 4-5 seconds.
CAUTION: Stalling the converter causes a rapid
increase in fluid temperature. To avoid fluid overheating,
hold the engine at maximum rpm for no
more than 5 seconds. If engine exceeds 2500 rpm
during the test, release the accelerator pedal immediately;
transmission clutch slippage is occurring.
(7) If a second stall test is required, cool down
fluid before proceeding. Shift into NEUTRAL and run
engine at 1000 rpm for 20-30 seconds to cool fluid.
STALL TEST ANALYSIS
Stall Speed Too High
If the stall speed exceeds 2500 rpm, transmission
clutch slippage is indicated.
Stall Speed Low
Low stall speed with a properly tuned engine indicate
a torque converter overrunning clutch problem.
The condition should be confirmed by road testing. A
stall speed 250-350 rpm below normal indicates the
converter overrunning clutch is slipping. The vehicle
also exhibits poor acceleration but operates normally
once highway cruise speeds are reached. Torque converter
replacement will be necessary.
Stall Speed Normal But Acceleration Poor
If stall speeds are normal (1800-2300 rpm) but
abnormal throttle opening is required for acceleration,
or to maintain cruise speed, the converter overrunning
clutch is seized. The torque converter will
have to be replaced.
Converter Noise During Test
A whining noise caused by fluid flow is normal during
a stall test. However, loud metallic noises indicate
a damaged converter. To confirm that the noise
is originating from the converter, operate the vehicle
at light throttle in DRIVE and NEUTRAL on a hoist
and listen for noise coming from the converter housing.