Right-O...just did my EF's head gasket. The car runs well but sometimes when at traffic lights when idleing it will hold revs at about 580-610 RPM and then after awhile of sitting there the revs will suddenly for like a second just drop a few hundred revs then come back up. It does this at irregular times. Also when idleling it will drop revs then start 'lumping' like it feels like the engine is about to stall...so I give it a few revs and it rights itself mostly. I havnt even done like 100km's yet since the head was done so could this just be a ECU relearning thing..or tuning...or something else?
Any hints?
Cheers!