when my preludes revs drop to about 1000 rpm it surges back up to 2000rpm and then drop back down can anyone help me to figure out why

 

lol you should have searched...very common problem either a fast idle thermo valve located underneather the Throttle body, sometime its an easy fix by taking it off and screwing a screw that has came lose inside or a idle air control. Also i have even heard worse problems as to having to swap ECUs if all else fails. For instance i pretty sure its my ECU due to the fact that i have swapped motor and it surged with the old motor and also the new motor at the same rate......so let me know

 

you could also have a vaccum leak somewhere.

 

search this, but just to nice...do the 92lude.com mod