Just finished puting engine in my wrx year 1995, everything is cool apart from the tick over is very low how can i sort this?? many thanks guys!

 

not sure if its same on classics but that happened to my blobeye after i disconnected the battery for a few days,drove around a for a day or so then it was fine.
maybe something to do with resetting ecu!
im no expert just a guess as this happened to me on two occasions

 

Have been driving it but still the same!!!