there are 2 tranny types used in this era.
real 3speed hyrdamatic, and 4 speeds with electronic TCm control box
to diagnose any tranny ,one must know what is there.
the storm is really Isuzu impulse.
the 2 choices day 1, was
- 3-speed Jatco F3A automatic
- 4-speed Jatco F403E automatic
so what is a F3A;
here is the gutshttp://www.shinseiauto.com/japanese/transtar/atmazdaf3a04.pdf
ever change part id 26 this decade? the Filter,..... called proper service.?
as you can see it\'s a real hydramatic, no TCM brain
as such , diagnosis is old school.
stuck in 1st.
so in the FSM book , the first test
is to do the stall test. (google that)
if that fails do the transmission line pressure test. (test ports)
the stall test, will be like 1500 rpm (no i didnt look yours up)
but of like very low, the engine is weak
if the rpm goes real high that it slip. and is end of road.
ok stall passes.
the next part to fix is the governor.
this device, causes the gear change, it its dead.
the car will stick in 1st.
the GOV connects to the tail shaft.
before the GOV , i change out the Vacuum modulator #30
this mod UNIT, can leak in side and cause no up shifts.
if it vacuum nipple here, leaks ATF , the MOD is bad,
i just replace them on suspicion,.
the GOV on this car has a nice cover #4. that can come off
one car , did this, the GOV had plastic gear, and was shattered.
that is about it, on the easy fixes on car .