running rough,misfiring,and spitting on 1990 Nissan Pickup (D21)

when i turn my ignition switch to the on position and look under my seat at the ecu the green light flash many times and then the red comes on an stays on an when i turn it to the diagnostics mode nothing changes the red light stays on

by in Boaz, AL on January 03, 2013
1 answer 4 comments
ANSWER by on January 04, 2013
seek diag or have codes read and post so we can adv
COMMENT by on January 04, 2013
You cant read codes.when i turn my ignition switch on an look at my ecu obd it flashes the green light many times and then the red light comes on an will not go off and when you put it in diagnotic mode nothing changes.its like the ecu is locked up or its messed up or it has a wiring problem
COMMENT by on January 04, 2013
count the flashes with green light it should code out like 1 flash then pause then 2 or so flashes then on to the next code
COMMENT by on January 04, 2013
The green light only flashes when you turn the ignition switch on an it goes off an doesnt come back on an then the red light comes on an will not go off. It doesnt give me any codes at all.its like the ecu is locked up.
COMMENT by on January 04, 2013
SEEK DIAG INSTEAD OF GUESSING THAT WORLD GET EXPENSIVE. TOW TO GOOD SHOP AND GET THEM TO INSP AND DIAG FOR U