1996 Dodge 4X4 1500 318

Need some more info if you could, does it do this all the time, what color is the smoke, does the engine light come on, is it hard to start.

It sound like your ignition is cutting out thats the black smoke (raw fuel thats not getting burned up), and with the engine light comming on same time. So its not starving for fuel like you thought but either getting too much fuel or not able to burn the fuel its using. Next question is you say it does it at 70 mph or could it be doing it at a certian rpm. Now your truck is a '96 so it might be able to read engine troulble codes with out code reader, try this with the key switch turn ON-OFF-ON-OFF-ON dont wait to long between cycles the check engine light will then flash a code (have pen and paper ready to write down with) count how many blinks of light, if more than one code than there be about 4 to 5 second delay between. (Example one flash pause four flashes 5 second pause two flashes pause two flashes = code 14 for the first and code 22 for the second)

Okay #12 is nothing(just means you disconnected your battery at some point) #24 is your t/p sensor show to high a volt good place to start, and # 27 is your #1 injector not responding (since you replaced that I would double check) #51 is oxygen sensor (probley becouse how bad its running) #43 is your ignition coil, So check your t/p sensor than you #1 ignition coil. Oh t/p sensor is throttle position.

You might check that T/P sensor again, I am not sure how you checked it before but if you could recheck with the connector attached to the sensor using a volt meter the center wire is your output terminal, with positive lead to that wire and negative to ground, with ignition on but not engine not running, throttle position closed should have 200 millivolts or more and at wide open throttle you should have less than 4.8 volts and voltage should increase gradually as the throttle is opened. Also T/P sensor when put on should be able to move a few degrees, if it doesnt that try to put on outside of socket tangs than there should be a little tension when moved.