My '86 SR5 has a similar symptom, but after once achieving 1800, it then goes to 2300 and back and then up again,
ad infinitum. I temporarily solved it by plugging the vac line to Switch "A" (immediately next to the EBCV) and reattaching it, but leaving the electrical connection attached. This was a maddening malady, making for some not-too-smooth driving.
The only downside is that the revs do not drop to near idle during shifting, but to a little above that; this has no real effect on driving,
per se, but probably wastes a bit of fuel. I still get 30+ on the highway, though.
I wrote the Mothership in CA, but have yet to receive an answer...
Now - others with the 3AC have had your problem; mine is just similar. I do not know if my fix will work for you.
The larger exhaust pipe mentioned would be of dubious help. Your gas mileage is fairly typical - the car is 20 years-old, with how many hundreds of K miles?
Incidentally,
DO join our Wagon-only Club at
www.tercel4wd.com, or the Forums at
http://Tercel4WD.com/forums . There are 400+ members owning the Wagons only; primarily 4WD, but also 2WDs. Automatics are welcome as well. Not much on neon and aero and audio and the like, but primarily concerned with keeping these little guys running. There are a
lot of
very mechanically-talented people in the Club, and a number of threads addressing the very subject you broach - but as always, do a
Search first (there are not ten thousand threads to search, either...).
There is also an FSM that you can download. Members are very helpful and also post new pop-ups on eBay and various CraigsLists.
Tom M.
PS: "biker" as in
motorized or as in
pedal-powered? There are a number of each in the Club, and I owned a bicycle store here for 30 years.
