The flooding starts with leaky injectors that wash the rings. Upon trying to start it you dump more fuel into washed cylinders where the engine can't overpower the dead cylinders spinning at low RPM. Holding the peddle at least in my car shuts the pump off so whats left in the fuel line, some goes into good cylinders and it will fire. Every time I have experienced this the engine fires only with a few cylinders til it gets back into life.
Might just be the way the 530 is.