89 century trouble codes

Help! I have a problem that acts like fuel, but the trouble codes are ignition. 35 says ‘ignition ground out of range,’ and another code, 42, that says ‘EST signal did not change when the ECM applied bypass voltage to the ignition module.’ These codes are not constant, but only intermittent. Operational symptoms are: frequently, but not always, needs ether to start, but will supply its own gas once it fires on ether; frequently, but not always, will stop delivering fuel unless I ‘feather’ the accelerator pedal. Any ideas?