90 5.7 wont hardly run, rich

My 90 2500 has been sitting for most of the last year. Always ran great. Started her up to try to sell her. Was sweeping the bed out and she started to stumble at idle. Black smoke began to exit the tail and she stalled. Only way to get her started again was with foot to floor. Black smoke and having to floor it indicated over rich. Unpluged one injector (there are two in the throttle body) and at least she wold run at idle. The moment you plug the second injector in she stalls. The one injector seems to be dumping more fuel than the other. Not a nice cone. I have never diagnoised this before so not really sure what I should see. Is the injector bad or somthing telling it to be extra rich? I need the gaskets for the throttle body now since I took it apart to look at. Can you buy the gaskets and an injector or is a rebuilt t.b.i. unit the better way to go? How much$? I was hoping to sell her for 1500. She has no dents or rot. HELP!!!
Trip

Disconnect the coolant temp sensor see what happens, then check the fuel pressure, if no change.

at idle the spray from the injectors should be a very fine mist, almost hard to see. if either, or one, injector is dumping fuel on there the injector is probably bad. stuck open or something. the injectors should be replaceable independently. good luck.

Good news. Bought a gasket kit for the tbi. Cleaned her up andput it back together with the old injectors. Wanted to try some of the sugestions I got. Well fired her up and the same problem came up, way rich. Unplugged the coolant temp sendor and she ran much better just would'nt idle. Replaced the sensor, plugged it in and she ran fine, just had to turn up the idle screw. Previously the screw had'nt even been contacting the throttle and she idled okay. (before my problems started) Could I have messed up that idle air control valve thing? I did pull the plunger thing all the way out but did reset it to less than 1 1/8 inch like the books say? Thanks for the ideas, anything on the idle?

hello i got a 1990 2500 and it ran good but it sat for a while and now it dose the same thing as yours idels bad and smokes black ....cant seem to find a fix ....well just seen this and wanted to know if you got yours fixed .....well if you read this could you email me
[email protected] thankx:banghead:

Where are you located? I'm interested in the truck. If its not to far from Florence, S.C. Thanks

hey i am all the way in hawaii ....its a bit far well i am not planing on selling to sell it .sorry

well i still diidnt found the problem i tested the fuel pressure and its good ..i ran it on a $5000 code reader and it did not turn up anything.could the rings be stuck in ?thats what i am thinking .i unpluged the water sensor and it still runs the same

you guys have a book, would check what i s making it run rich. if ect sensor is malfunctioning, it will definetly run rich, also may even have a stumble, stall or no start condition. start with some type of sensor check first. when you floor it, you go WOT and back into "open loop"? ! and bypass sensors so it will run temp.