Fuel Injection problem on Alliance

Hello I have a 83 Alliance with only 22K miles on it but it has a problem. It has a throttle body fuel injection setup and is running WAY to rich, so much that it wont run other than to idle it. Indications are thick black soot out the exhaust and the air filter gets soaked with fuel. ALso the engine backfires through the throttle body. Ive read the chilton book and performed the basic tests and it has not helped. Basically something is telling the injector to pump in too much fuel.

From the trouble shooting guide it suggested to change the Oxygen sensor on the exhaust which I did and no improvement. Getting the trouble code out of the ECU is a 3 which indicates a bad wide open throttle switch and or closed (idele) throttle switch which of course the book doesnt tell how to test either.

One thing I have observed, while its running for its brief time before stalling from flooding out there appears to be a leak at a gasket between the intake manifold and the throttle body lower base, can this cause this symptom?

So any suggestions are greatly appreciated. Its a car for my son and even though its 22 years old its like new if I could fix this problem.

if their is air leaking through the gasket the chances are it will be drawn to much air in and it is possible this could be whats causing backfire through the air filter but that would be down to it running far to lean.if you could remove the throttle body and check its position that may help you.
i would suggest first of all trying to get your hands on a fuel pressure guage and connecting it into the fuel line,crank the engine and check the pressure as if its pumping far to much fuel maybe the fuel pressure regulator.
failing that reply to this post and i will give other instructions

Hi All, Ive sent the car to the garage and letting the 'experts' figure it out. Thanks for the help and Ill let you know what they find.

~ Phil