1987 CRX Si, bone stock. Occassionally (maybe every other day, not outside temperature related) the car will start to run rough, almost like a cylinder is not firing. Checked every aspect of the ignition, every within specs (plugs all light tan, good). All the fuel injectors are ticking. No ECU codes. Once above 40mph (2nd,3rd,4th,5th gears, no difference), it feels like its running fine, but below 40mph it bogs down horribly. What else to check? I was thinking the fuel pump, but why would it run fine above 40mph? Any help is greatly appreciated (it's my brother's car, I'm trying to figure it out for him).