Fuel injected engine starting methods can generate massive threads, even on a site that covers just one make of aircraft!
The first question to ask is why does the POH method not work. If it does not work, there is something wrong and the aircraft should not be flying. End of story. Cold starts should be very reliable.
That said, hot starts are often problematic. Especially if the engine is not quite "hot", say after being stopped for 20 minutes. I suspect that a common culprit is fuel vapour in the pipework. The POH hot start method should also work for a truly hot engine but the intermediate cases can be a problem. It can take a lot of cranking to get it going, say 5 seconds (which seems a lot).