82 xj 750

when i start out my warning display go's through its test cycle and
every thing can be o k. after a while it starts to get weird. when i
slow down the whole list comes on and i get a solid red warning light.
then if i punch it [accelerate] it goes through the test cycle and
it's all good till i slow down again. what is that??? for now i'll
just cover the red light.

 

Sounds like a voltage issue. Check out the voltage rectifier/regulator
circuit. If the engine computer senses low voltage it'll reboot which seems
to be what's happening.

 

May also be the battery, since it seems to have enough "juice" when the
engine is off idle.

Sure Ace, you just keep doing that..........for, oh about one
day.........after which it won't start.

 

Not in order of testing, but check the following:-
Battery in good condition with sufficient electrolyte.
Charging voltage, it should be 14.2 - 14.8 @2000RPM and above.
Battery terminals clean.
Earth lead making good earth, check the voltage drop.
Verdigris on any of the connectors going to the display, triple check the
multiblocks.