really weird problem

I have a 2001 sonata with 2.4. Engine runs great, but when the throttle is at a certain position, usually around 1800 rpm, the engine will drop to 1000 rpm for about a second and then recover to normal. Now, the drop off and recovery are both very abrupt, so when it happens while driving a fairly sharp jolt is created. If the throttle is not moved, the rpm will drop and recover over and over until the throttle is moved to another position. This is a problem that is very predictable and will happen in park or will driving in any gear.( it's an automatic) It definitely seems to be triggered by the position of the throttle, so it must be the tps sensor, right? But no codes are thrown and when I connect a multimeter to the sensor, readings seem normal. At idle, reading is .36 volts and rpm interuption consistantly occurs at .67 to .71 volts. The reading never fluctuates during interuption. Any ideas would be appreciated.

Sorry it took so long, but I fixed the problem. The voltage value at idle of .36 was too low. I adjusted it to .50 and it runs like a champ. No more hesitating and jolts during acceleration. Hope this helps someone.