You do not have Cal emmissions, so you do not have CIS code retrieve
[ socket #3]
That was not until 1990 on 124.030

You can go to 6 and 7 by using1 for ground of the tool , red of tool to bat +, and odd to the pin# ..but I think you want engine management codes , which your year does not have. [ only Cal]

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A Dalton