Help with hesitation at high RPMs - fuel starve?

[KnifeySpoony]

Ok so issue with my car today. Recent build 420R, duratec with RBTBs. Trackday number 8 with the car, has performed flawlessly until today. In the third session at Laguna today, I let the fuel get a little too low, and got fuel starve (in a right hander, I believe). POPOPOPOP for about 1 sec, so I quickly dialed it down and brought it in. When I filled up, it took 4.6 gallons to fill it. Not sure if that is the expected level to risk fuel starve. The track ran out of 91octane so they only had 101, so I filled up with the 101 (had also topped up with the 101 with about 3 gallons when I got there in the AM). 



So the next session, car starts/idles without issue. I go out - warm up lap, short shifting around 6k RPM, no issues. Car is pulling hard and smooth. Second lap, start to bring it up to pace. When WOT, as the revs hit about 6k/6.5k, it starts to hesitate like it's missing. I immediately lift, but next straight same thing, so lift again. After a couple more times and realizing I wasn't imagining things, I pulled in. Looked over the car, everything seemed in place. Next session, same thing - instead of lifting when it occurred I stayed WOT and as the revs slowly climbed,  heard popping from the exhaust. Also, if I would accelerate at less than WOT, the car would pull smoothly all the way to redline.



SOOOO, I would guess there is some kind of restriction/limiting factor in fuel delivery? Is it possible getting fuel starve somehow damaged the fuel pump and now it isn't able to provide enough pressure to go WOT above 6k? What else should I be looking at?



Thanks if you made it this far!

[BertBert]

4.6 us gallons is only 17 litres, so the fuel shouldn't be low enough to cause fuel starvation in my view. So the original problem is likely a fuel delivery problem, pump failure, blocked filter etc.

Love Laguna Seca BTW, Done a lot of laps and air a few races there. One day I'll drive it in real life, not in VR!

To your problem, I'd check the filters, fuel rail pressure etc.

[DCL]

The fuel bowl is filled in two ways - via suction from a venturi which is fed with a bleed from the high pressure feed, and in the top through holes when the tank is full enough. So 'running out of fuel' does not need the tank to be empty, but simply low enough to allow the bowl to be emptied if the venturi is not working.

The symptoms you mention suggest to me that the venture in the pump is blocked. I suggest removing the pump and cleaning the filter and venturi (the little orange bit)

[KnifeySpoony]

Thanks gents. I will dig into the pump. Could starve cause damage/overheating?

[KnifeySpoony]

Also it has come to my attention that the pump is in the left side of the tank, so I should not have encountered starvation on the right-hander like I did. This makes me think that the fact that I was in a corner during the first episode is a red herring, and that it was never G-induced starvation. I think something just failed and that was when it was first evident.