Mitsubishi Repair: 1996 galant 2.4 wont idle, mass air sensor, fuel emissions

Question
QUESTION: My sister bought a 1996 Galant S 2.4 for dirt cheap knowing it didnt run. When I looked at it, it had no spark cuz the last owner took the distributor apart and couldnt make it work again. I replaced the distributor with a used matching one (I have spark). I can make it run if I hold the throttle to or above 10% Throttle position (750rpm), if it goes below that it detonates and kills it self. Timing mark read @2000rpm 5 BDTC and Scanner says 9 BTDC, at 750rpm (10% TP) it reads .5 ATDC on the scanner. I have NO engine codes .... Im lost at this point... possibly IAC needs to be cleaned, or tested? if so, do u know the parameters for testing?

ANSWER: Mike,
The detonation may indicate an extra lean fuel mixture.  Check to make sure your fuel system is working properly.  Inspect the pump and try replacing the fuel filter.  It may be a good idea to clean out the injectors.  Also check your mass air sensor at your air filter.  The procedure to inspect the IAC and many other components and sensors can be found in service manuals such as Haynes or Chiltons.  These are offered at many auto parts stores.  You may even have luck searching on the Internet for the procedures.
Good luck!

---------- FOLLOW-UP ----------

QUESTION: just today as I was running the car for about 5 min at about 2000rpm (did not change anything) and the car started smoking, the exhaust was literally glowing from end to end, slightly melting the undercoating of the car... plus I put 2 gallons of gas in the car yesterday, after that 5 min run, it ran out. I was thinking too much gas was dumping - but i can see your point and will look into the fuel system. Thanks again

Answer
Mike,
From your latest information, I can tell that you definitely have a fuel/emissions system problem.  But instead of running too lean, you're right in assuming your running too rich; way too much fuel.  The red-hot exhaust is caused by the catalytic converter trying to absorb/burn all the unburnt fuel that was not combusted in the engine.  The most common cause of a rich fuel mixture is a damaged oxygen sensor.  Your car has two O2 sensors; one before the catalytic converter and one after.  I would replace both at this point, since the super hot exhaust may have damaged both.  It's strange that you would not see a check engine light for a bad O2 sensor.  There may even be a problem with the car's computer.  But start with replacing the O2 sensors and see if you get a little farther.
Good luck!