service engine light came on after changing fuel pump.i broke a plastic breather or vent next to fuel tank. Would that be the likely problem?

 

might be. just borrow a scanner from autozone and find out what the ses light is.

 

If you check the mainpage and loko in the Tech articles, you can check your own codes by watching the SES light flash.

You need to locate your ALDL connector, '86 should be to the right of the steering column., if it's not lost, the plastic cover will say ALDL or Diagnostic, or similar.

Turn key on to "run", jump upper right two pin (next to each other, not upper right and the one below it), and insert a paperclip between them.

The SES light will flash once then pause and flash twice, then repeat twice more.

This is a "12", disregard this, it occurs because key is on and no dizzy pulse are seen. Then after flashing the code 12 three time, any codes stored will be displayed...i/e flash-flash pause flash flash flash would be code 23.