Recently installed TBI unit in 83 Jeep CJ-7... Complete donor engine and TBI system from a 89 GMC G3500 Box Van.. ECM 1228747

Got it running after setting initial timing with bypass unhooked. Plugged bypass back up and it surged on idle. After checking several things I unplugged MAP and it idled much better. Checking senor with vacuum pump and referencing against chart (inHg/Volts) it functions properly.