Toyota Repair: 1993 Toyota Landcruiser engine light flicker on and off, toyota repair manual, light flicker

Question
Diagnostic codes 83, 84, 85 are showing that they are the problem.  No one seems to know how to fix this problem.  Would you be able to help me please.  The engine light will come on and stay on sometimes 5-10 minutes.  Then it goes off and will come on eventually again.  We can't seem to find out why and the Toyota repair manual does not help my mechanic at all.  I have had the transmission replaced 2 years ago.  No real problems with the vehicle other than the transmission slipping and a new one installed as a result.

Answer
These codes indicate a failure of the electronic spark advance system(ESA)the on board computer controls the spark advance, there may be a problem with the distributor or possibly the ECU. The factory repair manual gives complete instructions how to check this, I suggest that you take it to a Toyota dealer to have this diagnosed.