1995 pickup intermittent engine light

[maxpickup]

Mystery to me and my mechanic -1995 pickup 3L 5 speed 208000 miles- engine light comes on sporatically, usually until RPM gets to around 2000. Then it is off until it drops below 2000. Yet, sometimes it doesn't come on at all. Mechanic tried to pull codes, but the EFI would not give a reading. Engine seems to run well though a rich. Any ideas? Thank you

 

[turbo8]

This is in the wrong forum, but it's pretty easy for you to get the codes on that model.

You just have to jumper two pins on the diagnostic port inside the engine bay then count the blinks of the engine light.

 

[maxpickup]

Thank you and I apologise. Which forum should i post this question in?
I have tried the jumper technique but the engine light remains solid.
Thank you again