I got a code 43 what do it mean

1994 Jeep, Cherokee?

check all EFI system fuse first with a meter.

that is ASD drop out.
all jeeps from 93 to now have ASD relays.

43 code (nice checking you did) is bad spark.
when the PCM sees bad spark it then shuts every thing down

http://www.fixkick.com/Jeeps/ASD.html

cause is bad ignitor or coil.
the big v8, with the funny locking throttle body... short.
that is true if you crank for 5 full seconds.
to see if CMP sensor fails too.
cmp cam sensor is in the distributor base.
the ignitor is in the PCM, and drives the coil directly.
i presume spark is dead directly at the coil terminal
and is dead the first 2 seconds cranking. right.
takes 2 person to test spark. one at key , 1 and coil
the PCM only allows 2 seconds for spark to happen
if it fails ,it kills the ASD relay.
making trouble shooting tad hard , for those that dont know jeep ASD issues.
if the 5.2L cmp and CKP sensors work right, the PCM then creates spark
it does this via and ignitor.
the coil can be bad, as can the rotor and cap. id replace any old cap and rotor, fast. if the coil tower terminal HV. has good spark.

read failure to start test here
http://www.jeep4x4center.com/knowledge-base/index.htm?utm_source=cj#service
chapter 8D-6

and page 8w-30-4 , coil schematic.
as you can see, the coil has 12vdc key on for 2 seconds.
cranking.
the PCM ground the minus coil pin.
this charges and fires the coil
the ignitor transistor is in the PCM on this car.
The PCM monitors this pin minus , and if it fails to pulse,
it knows the Coil is dead. and then shuts down EVERYTHING EFI wise.

that is how it works.
tricky yes,but true.