Deactivating one EUI at a time will identify misfiring or dead cylinders. As mentioned previously, current values are high, and for your own safety, do not tamper with EUI wiring while the engine is running. Professional-quality scanners can safely deny power to the injectors so that the effect, if any, on engine performance can be gauged. When a weak cylinder is located, replace the injector and retest. If a new injector does not solve the problem, check valve lash to make certain that the valves are seating and, if necessary, make a cylinder compression. Caterpillar technicians use a boroscope, inserted through the injector mounting boss,to visually inspect cylinder internals.