For starters, it would be a good idea to check all the electrical
connections associated with the transmission. Make sure the trans linear
gear position switch, decoder and transmission ECU connections are clean,
tight and secure. Likewise, its an excellent idea to check/replace the
transmission power relay. Most of these problems are related to poor
electrical connections! Its also smart to “reboot” the ECU by removing the
negative battery cable temporarily.
Your 94 has a starter logic circuit (microprocesser with multiple inputs)
which is different from the 92 and earlier models. I doubt if it is the
root cause of your problem though.
The “Fuel Fail 69” is an infamous diagnostic trouble code (DTC) that pops up
from time to time. The Engine Management ECU thinks the car is NOT in “park
or neutral” when the car is first started. I had this DTC on my 90 XJ6 and
could never determine a root cause to the problem. However, “Haynes”
suggests the DTC 69 problem (at least for my model) is related to low
voltage (at starting) as sensed by the ECU. My car would ONLY start in park
or neutral as expected. I simply reset the ECU (removed negative battery
cable) and the problem has not resurfaced for over a year now.