[Healeys] Fuel problem--BJ8

[Tom Felts]

Recently have developed what I feel is a fuel starvation problem on the Bj8.  Happens very seldom.

History:
there is no filter inside the tank---removed years ago
I have replaced the in-line fuel filter that I installed after removing the sock filter inside the tank.
the pump points were pretty worn, and I have filed the inside ones down and added a new "outside: "flexible" one with fresh points on that side.
I have a back-up pump in the line
System has worked flawlessly for 12 years.
Starvation appears when outside temp is high and car temp is high.
when I say starvation, I mean it starts to skip and miss---does it for maybe 10 sec and clears up and car runs very smoothly.
all lines are in good condition and there are no leaks from the fuel bowl or lines.
fuel cap appears to be non-vented but I have used this cap for years with no problems at all.

I'm open to any advice and/or suggestions.

thanks
tom