i need help i just bought an 87 crx si and while i was diving it home the pgm-fi light comes on and the engine revs to 3000 rpm and then drops to an almost stall and repeats the same thing all over again when I'm at an idle need some help with finding out what it could be any help would be a big help thanks

 

Check the vacuum lines. Make sure that none are cracked and that any rubber plugs are tight on the manifold. Also make sure the PCV is working properly. Good luck