Normally I'm all about the searching and FAQ's but I've not got the time, deadline for this car working is next Wednesday! Road trip to V-fest in Calgary and I still need to break in the new engine. The car: 1990 crx si, b16a swap, running PW0 (OBD0) ecu, engine has been completely disassembled and rebuilt including all bits and pieces on the IM and head, new vtec solenoid filters... disassembled and cleaned up IACV... etc. timing is perfect cam wise,couldn't set distributor timing because of idle issue ,2p service connector has no effect on idle either. The problem: Started it for the first time last night, started fine, ran up to temp with no issues, 2000-2200 rpm cold idle. Then once it got up to temp idle dropped to 800 then kept surging back and forth 800 to 2000... 800 to 2000, no cel though??? And it doesn't miss it just keeps loping. I let it cool down and started it again and same thing... I didn't have my factory service manual with me at the shop so I didn't check anything... I'm bringing it tomorrow so I'll just start troubleshooting after work. Just wondering if anyone could save me the time of going through all the components if anyones had the same problem, what should I check first? thanks for any thoughts.