Fueling problems

[mk6gtracer]

I'm running an LS1, cammed with 45# injectors. Mafless . I had 750 almost trouble free miles, (the car bucks at slow speeds.) I took it to Roebling Road raceway for some track time( 2.2Mi road course) It ran fine for the first 3 20 minute sessions. It then would hesitate badly off of left hand corners. The tanks were 3/4 full, but it felt like a fuel pick up problem, so I topped off. The problem got worse to the point I parked it. At the end of the day I droave it 60 milles home w/o incident. Two weeks later ( and 15 deg higher ambient) I drove it to Hutchinson Island for some parade laps behind the pace car. The problem was even worse. The throttle will not pick up out of the turns. It Finally quit altogether on the way home. Feels just like vapor lock to me. Any thoughts on where I should be looking?

[1meangto]

Will it start after it sits awhile?
Do you have any logs?
Do you have a wbo2 in the car?
Have you checked fuel pressure?

[joecar]

So it hesitates when you turn left...?

Is there any wiring/plumbing that is fouling in the front steering/suspension or rear suspension...?

Do you get any DTC's...?

Do you have any lose ground connections...?

If you jack up the rear on one side (to simulate a left turn and/or a right turn) can you make the problem happen while in neutral, measure fuel pressure.

If you suspect vapour lock, inspect the fuel line under the car, is it exposed to exhaust pipe...?

Check the fuel pump relay, tap on it while engine is running... swap with another relay see if the the problem happens.

[mk6gtracer]

Thinking it was vapor lock I let it sit for a while. It started right up, but only ran for another couple of miles. I have a log, but I am out of town until Monday, I'll post ti then. I do not have WBO2 sensors. I have checked the fuel pressure with a manula gauge, its at 58#

[mk6gtracer]

It started out hesitating in left hand turns, it then began hesitating in both left and rights. And finally, it quit in a straight line. No DTC's I will check the grounds and wiring when I get back from this darn trip. The car is a mid-engine, McLaren Mk6GT, so a saddle tank on either side connected via a balance Line. Pump is a standard in-tank unit feeding through a filter/regulator in front of the engine, so nowhere near the exhaust. But the engine compartment is pretty hot in general and it sures seems to be heat related. I'll change out the fuel pump realy as I have a spare. Thanks for the ideas!