If the injector’s won’t seal they produce drips as they sit with system pressure on them. The most common symptom is hard semi warm restart. They won’t effect the cold start much because the engine needs more fuel anyway, however when the injectors drip into the intake manifold on a warm engine the drops create lots of fuel vapor and that tends to flood the engine causing long crank times. Some of the Rochester Multec fuel injectors are known to have this problem.
We do a before and after leak down test to verify the condition of the injectors. If the seats are worn then cleaning won’t solve the problem. We leave the injectors in the bench for 10 to 15 minutes with 3 bar pressure on them to see if they drip. The injectors in this picture were forming a drop about every 15 seconds. If we find you have a set with worn seats they will need to be replaced. We only charge for injectors that we can bring back to like new performance. If you need your Brine injectors tested and serviced check at our service web site for more information.