Intermittent failure to turnover - '97 Boxster

[DWSTOWELL]

I just replaced the MAS on my '97 Boxster @ 55,000 miles. The
car runs fine, idles and accelerates properly. No "check engine" light
appears. No other adjustments were made. Battery was disconnected.

I live in Greenville, SC where the July temp is 88-90. Now,
intermittently, the Boxster will fail to turnover after a short drive.

So far (6 outings), it will start within 10' of the first try after initial trip
and and run fine. Battery is new; starter is, likely, original, but shows
no signs of failing.
I have had trouble in the past pumping a FULL tank of gas into the car.
Today, I made sure the tank was completely full ... took 5 tries after
initial auto shut-off.
> Any relationship to new MAS?
> Any other sensors failing?
>?
THX! Doug Stowell