94 honda accord ignition timing issuez

so i decided to buy this car as a project car really mint i must say for its age…well to the problem i replaced the distributor with a used one from the salvage yard it costed me 50 bucks…. so i loosened all the bolts to set the timing i started the car and it start having a weird idle it would rev to two grand and then 1 grand and continue doing that until i put a load on the engine ie. put it in drive so i was frustrated… i tested the iac cleaned it out same problem so ifigured it was the throttle position sensor tested that as well it was in working condition so i thought it was something to do with the distributor i started it and i strted playing wih the timing nothing so i tried something else i took all the bolts out on the mountong brackets for the distributor and started the car again and i retarted the timing even more and the irratic idle sttoped and it was running perfect…what would be the cause of this is it aa mechanical timing issue the cams r not lining up or somethkng???? please helpp