I just installed BC 272 cams on an Evo 5 & idle became so rough the car would easily stall. AFR kept fluctuating at idle reaching as low as 10:1. Vacuum reading is strangely high!
Both cam gears are centered at 0. I also, had just installed a new Walbro fuel pump too.

I had installed similar cams (BC272) a few times before, & never had such issue! In fact they barely had any cam lope!

I'd appreciate your suggestions

 

very cam timing events with a degree wheel on the crank and a dial indicator touching a valve. probably hard to do with the engine in the car.

 

Need new tune.

 

Too many things installed at once w/o tune
the fuel pump will increase pressure and cause a rich condition.
As for the cams-- did you pull the battery cables to reset the ecu to at the very least attempt to stabilize the idle? Bigger cams wont run on small cam AF settings.
As sated above-- get it tuned.

 

I solved the issue, strangely the problem was caused by carbon build up on one of the valves! Carbon buildup obstructed valve movement since valves moved further upward after installing higher angle cams.
A tune or the lack of it, won't cause such issue with 272 (stage 2) cams on idle.