'86 GT Coupe fuel problem

[Allan Jones <ampj@tiac.net>]

I need help re: '86 GT Coupe fuel delivery problem. My car would quit
while driving along at no particular speed(ground or engine), and then
would not start right away.  This happened more and more frequently and
then it became harder and harder to start until. . .well, it now sits in
front of my house. I did not notice any noise(doesn't necessarily mean
there was not noise though, and I do know what to listen for from
experience w/ VW fuel pumps failing). I know where the pump and filters
are located and have already changed the secondary?(bigger of the 2).
One lister answering a previous post stated that the dirty filter should
have tipped me off that the pump is the problem. It was extremely dirty
w/ rust and debris, but it was also old. Another lister posted: 

"When this happened to me in my 85 5000 it was the fuel pump RELAY! It
would overheat when there was a big fuel demand, cut out, cool off,
restart. Mostly without coming to a complete halt. Good luck David" 

  So, if anyone can answer my questions below, TIA.
    1.Is an extremely dirty filter and a description of the problem
enough to go ahead and replace pump without further diagnosis? Or as
another lister wrote:

"Are you sure it is the fuel pump?  You can test it by applying 12v to
the fused power connection and measuring the volume of gasoline that it
moves. There is a minimum spec in the Bentley for a correctly operating
fuel pump. Does it cut out during steady-state running, or when
accelerating?  If it occurs during steady-state rpm's, then I would
suspect something else, like an electrical problem.  Many different
components could cause the engine to cut out, make sure they are in good
condition (e.g. ignition system, fuel injection control system, etc.)."
 
    2.What should I hear from the pump NOW THAT THE CAR IS DEAD when I
turn the key to the start/on position and what will that noise tell me?
If I hear a noise that represents a good pump, should I stil test it as
above? If so, how exactly?
    3.How do I test the relay(if possible)? My problem seemed to be
closer to David's description("cut out, cool off, restart. Mostly
without coming to a complete halt") thus I'm leaning towards relay.
Where is it and how much should I expect to pay if it's bad?
    4.Would this pump/fuel problem have anything to do with my digital
dash's absolutely confused trip computer(fuel gauge inaccurate, M.P.G.
AVE. completely off(ranges of 8.0 to 54.5?), and miles to go utterly
deceiving)?!?
  I hope to tackle this problem this week and hope to have help from all
of you knowledgable helpers out there. . . .! I can't wait to try this
double de-clutching thing . .
				Thanx
					Allan