1987 tbi obd check no response / no code 12??

[olllie]

hi guys, Im lost and need some advice..

trying to check stored codes in my 87 1500 5.7 700r, jumped a and b with key off turned key on and i have no blinks. good obd ground and 5v.

When I set timing and disconnect the base idle connector the service engine soon light seems to work, and i have seen it light up for what I think is an egr code. But its very rare that the light turns on. I have had no egr for months.

Can't seem to be able to get any flashes, no 12 or any blinks at all. Any ideas where to start with this problem???


thanks!!