1991 Infiniti G20 Question: Car decelerated

Did the Check Engine Light/Service Engine Soon light come on or has it been on? If the car was running fine and slowly decelerated until it came to a stop it could be fuel related (fuel pump failed), ignition related the car would have just switched off or misfired. If the Service Engine Soon light was on the on board computer in your car will have stored a code indicating what area the problem may be related too. The distributor fail on this engine but the car needs to be checked by a mechanic before guessing what is wrong. Its hard to just guess what may be the problem without being able to do some diagnostic tests first hand.