idle problem

[newbie2]

hi, got the car back after the engine rebuild and it now idles like a pig, i started it tonight and it was idleing at 2k rpm for around 1 min then dropped to 1200 then started to go up and down from 1200rpm to 1500rpm. as soon as it hits 1500rpm it drops to 1200rpm and vice versa and does this quite fast like a surge and carried on doing this even when it was fully up to temperature. anybody have a idea what could be wrong ?
i cant do a fault check because i have a apexi fc ecu without the commander.

 

[Mr GTiR]

Sounds like an ar leak and it's hunting. Do a search on how to find an air leak. Sorry just really tired atm

 

[m34ts_pulsar]

when i had my new engine put in thats the idle i have - exactly what you have said! its still like that now!

 

[newbie2]

when the engine was being rebuilt i had a hks copy bov fitted, couls this be the problem ?

 

[shinny]

i had/have this problem now sent it back to garge it had an air leak throttle bodies to head but didnt stop the hi rev's just found out the garge didn't no how the vaccum pipe system went might be worth looking here first