Hi all.  On a recent trip, after driving for around two hours, I began

to notice an intermittent power loss.  I still had a good hour or so
to
travel, and was in NYC rush hour stop-and-go traffic without a cell
phone.  So I kept driving, at first noticing only every few minutes a
temporary power loss, which seemed to clear itself up within, say 10 to

thirty seconds.  Kicking the accelerator seemed to have no effect on
when it would recover.  When the car was in park, at that point, it
seemed fine when I revved the engine.

The problem progressed, though, until it began to stall out.  It would

slow down to an absolute crawl, regardless of the gas pedal position,
then stall.  It would then generally restart, but would stall again a
few times.  I noticed that if the engine were off for a minute or two,

it would start right back up.  Eventually, I was stranded a couple
blocks from home, unable to get it started again.  I looked under the
hood for any obvious signs of distress, checked fluids, looked for
leaks.  About ten minutes later, I decided to try to start it again,
and it started right up- only to crawl that last two blocks, stalling
regularly.

Couple things:  the engine doesn't run hot- the needle stayed right in

the center through all of this.  Also, the loss of power was not
sputtering, like when one cyllinder isn't firing- it was always smooth,

even while crawling.  Fuel filter is a year old, looked new at last
oil
change, maybe 500 miles ago.  Also, the following day, I couldn't
replicate the symptom.  At least, not by running the car for 25
minutes.

So, it seems temperature-related.  Fuel pump relay?  Fuel pressure
regulator?  Fuel pump?  How can I tell?  And where is the fuel pump
relay anyway?

Thank in advance