QuestionI have a 2005 Hyundai Tuscon with 48,000 miles on it. Recently, it has been shutting down (all lights flash on dash and then it shuts down) when I am slowing down or driving very slowly. A week ago it shut down on a highway when I had a 1/8th of a tank of gas and started when I filled it with a gallon of gas. It rapidly decelerates when I press on the brake. The car was just checked out a six weeks ago by a mechanic and I regularly have all fluid and oil changed/ topped off.
AnswerHi, Courtenay. There are a number of problems that could occur with the fuel management system that could make your vehicle shut off. The fact that it was recently checked doesn't necessarily mean there are no issues; any problem can happen at any time. In addition, many problems won't show up until the vehicle is driven and symptoms are experienced. I am a little confused, however, about the statement "It rapidly decelerates when I press on the brake." I doubt you're trying to express to me that the brakes are functioning normally, so if you could expand on what this is intended to illustrate, it may be helpful.
Since you indicate that you were able to start the car after adding a gallon of gas, this has me wondering if you're running the vehicle out of gas. What normally happens when the car stops running? Does it normally stop running every time you come to a stop? Is there a gradual loss of power over several minutes leading up to when the engine shuts off? Does it start right back up or does it need to sit a while before it will restart? In the case where you added the gas, how long was it between when the car stopped running and when you added the gas? In this particular instance, did you try to restart the car after it stopped running? Am I correct in presuming that it wouldn't restart in this particular instance?
Often, problems causing stalling will cause diagnostic trouble codes to store in the engine control module (ECM). I infer that your check engine lamp comes on when the car stalls. Is it on while the engine is running or after you restart the engine after a stall? If so, this would indicate that you have a code stored in the ECM that may well give us information as to the nature of the problem. In fact, depending on the issue and its frequency, you may have a code stored even if the check engine lamp hasn't been on. So it may be worth your while regardless to stop by an auto parts place that will read your trouble codes for free. If you do so, report them (the codes numbers themselves, that is-- I'm not interested in what the parts store thinks is causing the code) in a follow up. I'll be happy to tell you what they indicate and what relationship they may have with your stalling.
So, anyway, below are my top picks for potential problems causing this issue. Your answers to the above questions will help me pick out which ones of these are most likely and which ones are not consistent with the answers you give.
-- Air hose has come loose from throttle body or air flow sensor.
-- Faulty throttle position sensor
-- Faulty crankshaft position sensor
-- Faulty air flow sensor
