Got some news....
Hi All, yes it was my doubt it's flame was weak and it confirmed being so, as watching some SQ videos on youtube I could see larger flames.
The news is this, today after coming home I put myself back at troubleshooting the dryer, I tried yet another time to let it run and with my big surprise it lighted up at first time and produced a very large blue flame, being almost the same circonference of the burner cone like it should be I guess , you could hear the flame noise being sucked as Jon describes...
It contunued to light up and shut off every 5 minutes or so for 4 times, till it stopped even if ignitor was keeping going red.....
So it means that is not gas pressure the issue as gas had neough pressure, so it 's something else...
So very likely is a coil issue (maybe not opening as they should because they got weak) at least I deeply hope so, gas shutting off prematurely or not lighting is a sign of bad coild valves as I've I've learned so maybe it is also for gas pressure....
And the gas trick someway allows valves to work a little even if not as they should.
I'm at work trying to unscrew the coils holder to check coils inside and eventually part number to find out if the ones I already found would work, unfortunately a bolt got stuck so I just hope the PB blaster I have sprayed will work, will wait for it to penetrate....
I hope that it will result "just" in a coil issue rather than a more serious issue like timer issue, I checked contacts with a current tester, and looks like the contacts work and current is sent...
If it will be the timer...well it's going to be hard...I will discover it just with the time.
Thanks all for the great help and inputs, please keep posting, I will let you knon any news I will have about.