if the 4 wheels are jacked up and the tire/rims spin easy by hand then they are not brakes stuck on.
mine came with both rear parking brake cables rust seized. and stuck engaged ! and dranging
so is the 2v carb still here,???? the horror of electronic controlled carbs?
many were modified, so we look or hacks there first. on all carbs this year. 87 too.
THE CARB IS complex
here is the 88 full carb controller schematic. called the BBD 2v carb.,page B-217 in the FSM manual factory service manual.
258cu-in, or 4.23Liters I-6 engines, the vin codes tell you what was there day 1 new. carb code 8384 (manual trans version)
page B218 shows all settings for the carb, for sure choke setting and be sure it released when engine is hot (180f = hot/normal)
coke 1 notch notch rich it states./
seem to me as the engine warms up to normal and the chock turns off, the carb goes lean and all real power (HP) is not on tap (right foot)
just a guess but IDK blind.
The MMC controls all fuel mix when engine is hot (means normal) it does that by modulations of the metering solenoids on side of carb.
and 1 O2 sensor
the carb this old may be just gummed up inside as they all loved to do 1920 to mid 80s when TBI came to play (EPA mandates)
the carbs then were fully dismantled and cleaned, all fuel paths and air. and jets. (all clean as a whistle)
complex carbs these are, nothing like dad had, in the 70s. or older
most jeeps this old are now modified. just to make it run.
if you take it to a shop and the see the
MCU metering carb they RUN for the hills (and justified)
but I can't see under your hood for MODS and hacks or such , not me, all I can do is guess it is
still stock and what we see below.
this is out of the Free FSM. 88 YJ,
Many of this electric carbs are now modified, and the 1st clue is the missing marked below metering devices.. wires cut to them a huge clue.
Some of this used vacuum metering device photo 2, that love to gum up.
as you can see last photo is the BBD 1987/89 fuel mixture control stepper motor, device, this is how the MMC controls mixture all the time.
most times we see it missing or wires cut to it and vast posts in calif failing dead hard for this device missing or hacked and failing smob for just the visual inspections in CALIF (< posted as a worst case to learn the ropes here)