The role of the fuel injectors is to supply precise doses of fuel into the combustion chamber. Both diesel engine and LPG injectors are electrovalves, which open for a time defined by the ECU (up to a few times per second). A broken injector will supply fuel in wrong amounts. Its failure may result in wrong injection timing, permanent fuel leaks or inadequate fuel spraying. A faulty valve affects engine operation e.g. it causes engine speed fluctuation, smoke, metallic clatter or power loss. In order to detect an injector malfunction you have to precisely diagnose the parameters of the engine and the injectors. Injectors should be reconditioned by a specialist workshop capable of calibrating them in conformity with the manufacturer's recommendations.