Mitsubishi Repair: acceleration hesitation in my 91 gsx, eclipse gsx, complete fuel system

Question
Recently i bought a 91 eclipse gsx 2.0 AWD turbo.  Today i noticed something strange.  while on the highway in 5th gear i stepped on it a little and there is very slow acceleration and a vibration. after i got into town i gave it some gas to let the turbo kick in and sometimes it performs fine and sometimes it will GO, then hesitate, then GO again and it just keeps hesitating uppon hard acceleration.  (NOTE at this time my tps was not hooked up because we think the sensor is bad cause of fluctuating idle when it is hooked up and fine when it isnt hooked up)
any information is greatly appreciated

thanks


Answer
Travis,
A faulty TPS can cause this problem, though it would typically set off your check engine light.  This can also be caused by a clogged air filter, fuel filter or EGR valve.  Check to see how dirty your air filter is, and if it's been over two years, replace your fuel filter.  The GSX sucks in a lot of fuel, and you don't want to strain your fuel pump more than it already is.

It's also a good idea to replace your PCV valve if your current one has over 12,000 miles on it.  They are cheap and easily replacable.  Your throttle body, throttle body elbow, and EGR valve should also be cleaned.  A can or two of carb cleaner will do wonders.  It's best to take them off the car before cleaning.  Try a bottle of STP Complete Fuel System Cleaner next time you fill up your gas tank.  Also, be sure you're using at least a 91 octane gasoline.  I know it can be a bit more expensive than regular unleaded, but it will help.

If none of those items helps, it's time to examine your car's computer.  Read this article for further information:
http://90gsx.com/eclipse/cap/caps.htm

If your ECU is mafunctioning, you'll end up with many strange, intermidiate problems.  Stalling, hesitation, and inability to start the engine car early signs of a bad ECU.  Pull it, and inspect for damage.
Good luck!