1994 check engine light on

I have recently swapped motors, i put a 1989 motor in a 1994. it will start and run good for about 15 seconds the the check engine light comes on and it runs rough. when you give it gas it bogs down but you can let off gas and it will run you can also pump the gas and it will rev up. I am wonting to check the code which i am unable to find the two diagnostic leads from the ECM. they are suppost to be under the hood release lever bu i am unable to locate. any suggestions on the location or probable cause? thanks for your help.