OKay I have a 93 stang i bought with a bad motor but a great notch body. It had a speed density wiring harness in it why I don't know. I had an 89 Mass air harness and computer to put in it. I also had a 87 notch body that was my daily driver. Ran great until about a week before I took it off the road (turned out to be a bap sensor) Anyway it had a speed density to mass air conversion on it. I swapped motors and put the 89 harness in. Got it started and it Idled at 1500 and was sucking up air like crazy. The air intake tube was LOUD. anyway it also ran real rich and blew BLACK smoke out the tailpipes. Took it out for a ride and got 7.521 miles to the gallon. changed the O2 sensors no help. I then checked vacum leaks couldn't find any. I am running a steady 14-15 lbs right off the manifold at idle. I then took off the 89 harness and converted the speed density harness out of the 93 to mass air. it brought the Idle down and the intake now sounds normal But I am still pushing back smoke at Idle and acceleration from a stop. At idle the car sounds like it is loading up and does push black smoke. Chaged the fuel pump from the 93 (aftermarket) to the one in the 87. Drove it got 10.5 miles the the gallon At wide open throttle it seems to be good. Please Help. I can't pull codes the code reader gets nothing. And I have tried to different readers. Help me please. I want to keep it fuel injected but at this rate I will go carb