i replaced my engine (87 305) with a 305 from an 88 Trans Am (TBI)... (i'm taking the old engine apart to see why it mixed oil and coolant.) the engine starts ok, revs to about 1k RPM then drops to 500 and then it chokes and the needle bounces between 500 and 0 RPM, after about 7 revs or so, it stalls. When i give it throttle, it stays running... i just have a problem with the idle.. i get code 42, Electronic Ignition Control, anyone know how to help me out?