Advanced starting issue!! please help!!
visual is not good enough. you need to put a gauge on it and see what the fuel pressure is doing.
one of the six other injectors may be leaking down. You want you injector flow rates to be balanced so if you find a fuel pressure leakdown condition from the injectors...replace the other 6.
all the starting issues you are having are textbook injector leakdown symptoms. the engine is basically flooded after the fuel pressure leaks down into the cylinders.
If it were me, I would put a gauge on the fuel rail, prime the system and check for leakdown. if there is leakdown, block off the feed, prime and recheck, if it is still leaking down, block off the return, prime and recheck. if its still leaking down, its the injectors as you have already ruled out the fpr.
one of the six other injectors may be leaking down. You want you injector flow rates to be balanced so if you find a fuel pressure leakdown condition from the injectors...replace the other 6.
all the starting issues you are having are textbook injector leakdown symptoms. the engine is basically flooded after the fuel pressure leaks down into the cylinders.
If it were me, I would put a gauge on the fuel rail, prime the system and check for leakdown. if there is leakdown, block off the feed, prime and recheck, if it is still leaking down, block off the return, prime and recheck. if its still leaking down, its the injectors as you have already ruled out the fpr.
Last edited by tech2; Dec 14, 2016 at 8:09 AM. Reason: clarify test procedure
it could be the coolant temp sensor. normally it works the other way round but if the sensor is stuck reading low it could be dumping too much fuel into the engine when it's warm. when the engine is cold it needs more fuel to start up so the computer takes care of that. if the sensor is stuck cold for some reason it's going to tune the engine to the assumption that the engine is cold and dump too much fuel to start up when the engine is warm. it would explain why the engine starts fine when it's cold and starts and runs like crap when it's warm. I'm kinda new to the Chevys but a lot of other manufacturers use separate temperature sensors for the signal going to the PCM and the gauge on the cluster. that means the gauge on the cluster could be reading fine while the sensor to the PCM could be junk and sending the computer the wrong info.


