I did a search for the EST thing but most of the stuff I got was for TPI. I have an 87 305 with the Q-Jet, does this make a difference?

 

Ok, I just replaced the cap and rotor and it fixed the code and the idle jumping for about 20 minutes and then it started to happen again. Does this sound more like a knock sensor thing? I have no idea about computer related things cause personally I don't like them, so if someone could point me in the right direction that would be more then helpful.

 

are u getting any codes? if so, what are they? If your SES light is on go scan the codes (theres step by step in the tech articile section of thirdgen.org homepage)

Idle jumping dont have nothing to deal with the knock sensor i dont think

possible things are a vacuum leak (spray ether around (not in the air cleaner of course) and if theres a crack in the hose, it will suck up the ether and you'll hear the engine rev...) also dont forget your HVAC line, its a hard line known for cracking.

make sure your q-jet is tuned properly.. i dont know much about them, does it smoke? what color is the smoke? the hto air snorkel may be icing up (known to happen on q-ets) from the cold

EGR valve? A bad Plug wire? i seen u replaced cap and such but u replace the wires?

 

I'm thinking the code is going away cause it only appeared once today but my rpms didnt jump. I'll do a follow up tomorrow and check sensors if i have time.