85 4runner w/ 22re and fresh rebuild. My truck starts and runs fine but after driving for a few minutes when i push the clutch to stop it idels up and down for 1 -2 minutes before normalizing. it does not stall or race. it just seems like it cant find where it wants to be. I do not have a tachometer but do have an oil presure guage and it jumps from 20 - 40 and then finaly holds at about 35. any ideas?....Thanks B.Johnson