Symptoms of Fuel injector problems.
#2
Sometimes when they get really sticky they will leak down... if you put a fuel pressure guage on the fuel rail then turn the ignition ot on you will see say 45 psi. Turn the key off and see how long it takes to leak down... in normal situations it can take hours for the fuel pressure to drop back... usually through the fuel pressure regulator. If it drops real quick you are often leaking down through the injectors... so if you start the car back up after waiting only a few minutes you have very rich lots of wet gas in the cylinders and a puff of black smoke.
Other injector problems are clogging and uneven spray patterns... you can remove the entire fuel rail and lift it above the cold engine... then have someone turn on the key and you watch for the spray pattern at each injector... you get a wide fan with mist...you can do them one at a time if you wish... just unplug the harness from each injector and repeat it over a small glass jar and watch and compare how they all play out...
or assume they are old and grimy and have a injector purge performed, their have bee good results with the chemical injected directly into the fuel rail and pressurized out to clean up the gum
good luck
Other injector problems are clogging and uneven spray patterns... you can remove the entire fuel rail and lift it above the cold engine... then have someone turn on the key and you watch for the spray pattern at each injector... you get a wide fan with mist...you can do them one at a time if you wish... just unplug the harness from each injector and repeat it over a small glass jar and watch and compare how they all play out...
or assume they are old and grimy and have a injector purge performed, their have bee good results with the chemical injected directly into the fuel rail and pressurized out to clean up the gum
good luck