Toyota Repair: 86 Toyota Pickup 4WD, 22R, 5speed manual trans, lopes, 22r motor, toyota pickup

Question
1986 Toyota pickup with 22R motor, 4 WD, 5 speed manual trans.
Pickup was running fine until I got stuck in the mud.  When I got out of the mud, left rear brake was stuck.  Got home and backed it off.  Now when the motor is running, it revs up and slows down continually or lopes.  Does not die. Motor was overhauled 2 years ago. Carb rebuilt about the same time.  Any ideas?

Jerry

Answer
It probably had something to do with getting stuck in the mud, but what?
Is this condition at idle only or while driving also?
It's possible that some water got into the distributor cap but that would cause an erratic misfire, engine loping or surging is normally caused by a leak at the intake manifold or a leak at one of the vacuum hoses.