Oldsmobile/Buick Repair: 1993 Olds 88: Hesitates when slow; no heat, throttle body injection, pressure tester

Question
Two questions:

When engine is cold, the car will not accelerate above 25 – 30 mph, regardless of how far the gas pedal is depressed.   The engine does not over-rev, and the transmission does not seem to slip.  After warming up for 90 seconds, the car instantaneously will start operating normally.  It will then operate perfectly until the engine is turned off and allowed to cool completely again.  (This has been happening for about 18 months;  the problem has not gotten better or worse.)   The “check engine” light has not turned on  (but the light does test ok during ignition).  

Second problem:  After changing the battery, the heater stopped working.  The only clue is that the digital temperature display on the dash now blinks for about 30 seconds after ignition.  (The display never blinked before the battery was changed).  Any ideas?

Thanks in advance for any input.  

Answer
Hello Paul,
For the heater, I would first try disconnecting the battery again for a few seconds, and see what happens.

The running problem sounds like a fuel filter...maybe the fuel leaking back into the tank, and slow to build up pressure.
I might also check the pressure regulator, but in either case, I would use a fuel pressure tester, and see what the pressure is.
Throttle body injection needs about 13 PSI all the time.

Van