A weakened fuel pump can cause the vehicle to take more cranks to start than normal, and in more serious cases may even cause the vehicle to require multiple turns of the key before it will start. 3. Engine Sputtering. One of the surest indicators of a faulty fuel pump is a sputtering engine — typically at high speeds. Here's what I've noticed: Every time I get in the car I fire the engine, hit the Stop/Start disable button, put the car into Sport Mode, and start driving. Next traffic light, the engine stops again like you forgot to clutch in on your old sports car. I think what happens is that changing driving modes turns stop/start back on again. The Automatic Start/Stop (MSA) system is a further BMW Efficient Dynamics measure aimed at meeting BMW's commitment to reducing CO2 emissions and enhancing fuel economy. BMW, always a leader in innovative technology, will be the first automobile manufacturer to bring MSA technology to all new models. If long term goes UP, you have either a bad MAF or a bad fuel delivery . Example: Idle long term: -10 Rev up to 2000, LT goes to 0%. You have a bad MAF sensor or bad fuel delivery problem . You let the gas go back to idle, LT goes back to -10 again. If these scenarios do not apply to you, stop spending more time on it. The auto start/stop function is a simple tech feature that has a huge impact on fuel economy. When you come to a complete stop, BMW automatic start/stop kicks into gear and shuts off the engine as your brake pedal depresses. The second you lift your foot off the brake or turn the steering wheel, BMW automatic start/stop puts the engine back Auto Start-Stop function in BMW helps the vehicle to avoid unnecessary overconsumption of fuel by shutting off the vehicle’s engine instead of putting it in idling mode during a complete stop. Both the Auto Start-Stop and ECO PRO mode as part of the BMW EfficientDynamics work together to contribute to the lowered fuel consumption and emission So, if that part of the engine timing is off, the two can hit each other, which would likely result in the engine needing to be rebuilt if you’re lucky. The other scenario, the more expensive result would be engine need replacing. If the engine timing of the cam is off, your car will either be running rough or not at all. 07 118i auto stop start engine - doubting thomas : The car is advertised as 'the automatic start/stop function helps you to save fuel and reduce emisions. To do so the system automatically switches the engine off while the vehicle is stationary such as in a traffic jam or at traffic lights. John MS said: If the question is whether the starter will wear faster with auto stop start on than off the answer is obviously yes. It's duty cycles. That begs the question of how long before the starter wears out. My guess is it will last for longer than you own the car. You could have a bad module. Without a code reader, you can still start by checking powers and grounds and follow it back. So - if you're getting a no crank - start by checking if the starter is getting power or not. Assuming not, head over to the relays for the IVM (#2 & #4) and check the inputs and outputs of those. 5SXt.