1992 honda accord dx when its idleing it will rev up and down for no reason I took off a vaccume line next to throttle and it idled could this line be clogged?

1. yes a 1992 Honda accord has a map sensor and what accord do you have engine wise ?? because theres different codes 2. it could be a idle air control valve because if they get dirty they can cause the car to rev high low or even stall and cause the car to run crappy.

The most common causes for "idle hunt" is a dirty throttle body or faulty idle air control valve. The computer uses the control valve to regulate idle speed.
There could also be a vac leak somewhere.

i had the same prob on a toyota check out the fuel presure if its good its prob the fuel regulater i think it should have around 32 psi but call and double check that

check that the throttle cable is to tight otherwise air in the coolant line at thew throttle body

i have the same car on a lx and dx model carberated if you take off the air cleaner and the whole metal house looking down at the carb it ill be in the upper left hand corner under a bunch of vacum lines its a roung black knob hard to get to if is a lxi or sei there is a idle screw next to the throttle cable

Idle control valve can cause this or any number of things like an O2 sensor or throttle position sensor.

its called a honda rev. its very easy to fix too. ok look at the intake manifold and there is a circular looking pipe coming up. unbolt one of the two screws all the way and the other one just enought to turn the top. once you get the top turned stick your finger in there its almost like a vaccuum and turn clock wise untill it stops and your done. it is only two phillips head screws and its sitting right on the intake manifold in the front of it

It might just need cleaning. Spray some PB Blaster around the throttle arm where the cable connects to at the base of the carb, and see if that frees up the flaps. And while spraying, fiddle with the throttle linkage.

Check your MAP and TP sensors. Your throttle body may be having trouble determining position and is compensating by adjusting RPMs.

put the crank at TDC and the cam gear and TDC slip the belt on adjust the tensioner and then rotate the engine two times make sure the timing marks are still lined up then put it back together and try it if you have the timing off it wont idle right and if could also be the throttle positioning sensor