Cranking the fuel

[ph-kim]

I noticed that quite a lot of wubble pump action is required before you get to the required 2.5-3.5 lbs of pressure required. According to the plane manual, only 3 or 4 strokes were needed to build up enough pressure, so that seems a bit excessive.

I'm also not entirely sure about the bottom limit. I haven't been able to actually start the engine with only 2.5 lbs indicated on the gauge, but that might also have been just lack of proficiency on my side.

[Uncle Jack Simulations]

Hey ph-kim!
I believe you are mistaking the wobble pump actuation with the primer actuation.

I'll link you a video of a real PT-19 startup procedure (It is in portuguese, but the important thing to notice is how many times the pilot pumps that wobble pump):

And on your other question: You actually need a bit less than 2.5 PSI. 2.5 is listed in the manual in order to give you some margin on that setting, this is because fuel pressure escaped through the fuel pressure relief valve (you can observe this happening if you build up pressure, and go check the bottom cowling's opening. It will be dripping this pressurized fuel). I believe what happened is that you took a bit longer than expected to start the engine after the pressure was built.

Hope this was somewhat insightful!
Dan.

[ph-kim]

No I wasn't confusing the primer with the wobble pump, I've highlighted the part in the manual about it above (and by plane manual, I wasn't referring to your manual, but the real world one). But yes, that YT clip clearly shows a lot more 'wobble pump action' is required there.

The time between building pressure and starting could have been the issue, although I uses the 'make her cranky' helper button, so there wasn't much delay.

[CaptCrash]

The neat thing about manuals is they tell you what a new airplane should do. The wobble pump in the video has is in an unknown condition of repair and the lines after the pump have an unknown qty of fuel in them.