Vehicle will sometimes turn over, but not start
Sometimes my vehicle will turn over, but it won’t start. The crank sensor was replaced and a local import repair shop reported that they think it to be the main computer because the fuel pump is getting too much. Randomly the vehicle will start over and over, but other times it only turns and won’t start. Can you tell me what could be causing this?
Experienced mechanics share their insights in answering this question :
Based on your description, it sounds like your 2007 Mercedes GL450’s fuel pump may be randomly shutting off. This can be due to a malfunctioning powertrain control module as the repair shop told you. This can also be related to a faulty fuel pump, loose wire, faulty fuel pump relay, faulty ignition switch, or a clogged fuel filter.
I would recommend having your fuel pump’s electrical circuit inspected for damages and tested with a digital multimeter in various locations to determine if the circuit is performing its intended purpose. If any damaged wires are located, they should be replaced immediately as this can cause the symptoms you are having. It is also very important to check near the power distribution center under your hood for the fuel pump relay and see if any damages are found there as well. A certified technician from YourMechanic can diagnose your starting issue if you need further help.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
Check fuses and relays Mercedes won`t start, and there are no batteries? You`ll need to check the vehicle fuses. Check the fuses for these certain parts, which are important: starter, ignition, engine ignition, and pump. It may vary from model to model whether a certain circuit affects starting.
The most common reasons a Mercedes-Benz GL450 won`t start are a dead battery, an alternator problem, or failed starter.
If the fuel pump is not coming on, and the fuse and relay are good, then it may be possible that there is a problem with the pump or the fuel pump circuit. The first thing I would do is check to make sure that there is power to the fuel pump circuit, and that the relay is in fact sending power to the pump.
The most common reasons a Mercedes-Benz C280 won`t start are a dead battery, an alternator problem, or failed starter.
If the car cranks when you turn the key, but the engine won`t start, it could be because fuel isn`t getting to the engine. One potential reason for this could be dirty fuel injectors. Over time, the fuel injector nozzles can become clogged with rust, corrosion or debris.
If your vehicle won`t start, it`s usually caused by a dying or dead battery, loose or corroded connection cables, a bad alternator or an issue with the starter. It can be hard to determine if you`re dealing with a battery or an alternator problem.
Find the reset button on the left side of your instrument cluster. Press the reset button and hold it until your display shows “To reset: Press reset button for 3 seconds.” Push the reset button again and hold it in until the display shows the system has been reset.
Bad Sensors
One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn`t working, the spark plugs won`t fire, keeping the engine from starting.
There`s no such thing as an intermittent mechanical fuel pump failure. Any power loss, engine `choke` problems, etc. are being caused by something else. In a fuel injected engine, electric fuel pumps can fail intermittently.
The crankshaft position sensor monitors the position and speed of the crankshaft and other parameters that play an important role when starting the engine. If the crankshaft position sensor is having a problem, the vehicle may have intermittent starting issues or not start at all.
If your diesel engine won`t start, the problem could be the amount of pressure in the fuel system. The engine may not start if the fuel pressure is too low. Fuel pressure that is too high can cause damage to the exhaust system while also increasing soot pollution in the exhaust.
When your engine cranks but won`t start or run, it could mean your engine is having trouble producing a spark, getting fuel, or creating compression. The most common causes are problems in the ignition (for example, a bad ignition coil) or fuel system (for example, a clogged fuel filter).
The most common reason your car starts then dies immediately is because of a lack of fuel in the engine. This often happens because there is a small amount of fuel in the fuel rail, which helps to start the engine. However, there is no fuel pressure to keep the engine running.
Engines usually stop suddenly only if they suffer from a lack of fuel or sparks . An engine that stops dead without prior warning has probably had a sudden ignition failure – although if it locks solid it`s more likely to have seized.
It might be a battery or alternator problem.
Perhaps your battery`s dead, or your alternator, which charges the battery, isn`t working correctly. If the source of the clicking is electrical, the starter (a small motor energized by the battery that gets the engine running) doesn`t have enough juice to stay powered.
The most common reason your car starts then dies immediately is because of a lack of fuel in the engine. This often happens because there is a small amount of fuel in the fuel rail, which helps to start the engine. However, there is no fuel pressure to keep the engine running.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Vehicle won’t start, once it’s jump started it only stays running until you turn it off, then it work start again without jumping.
ANSWER : Hi there. There could be two problems here. It is possible that your battery is bad and will not take a charge from your alternator while driving. In that case every time you shut your car off you will not have enough juice to start it again. Inspect your battery – it should have at least 12.5 to 13 volts to start your car, if it doesn’t you will need to replace the battery. The second problem could be that your alternator is bad and not charging your battery, in this case you will need to replace your alternator. Both the battery and the alternator can be tested in your car. If you would like to have the car checked for you, a certified professional from YourMechanic can come to your car’s location to diagnose the starting problem and proceed with repairs.
Car was sometimes not starting, not even cranking when i turned the key then after a few times itd start. Now it ont start at all
ANSWER : Hi there:
Without being there to inspect your vehicle, or having information about what type of car, truck or SUV you own, it’s very hard for us to give you some advice. You might want to have a professional mobile mechanic complete a car is hard to start inspection; so they can come to your location and determine why your vehicle is having these issues.
Cranks over start than dies
ANSWER : Hi There,
The idle air control valve is a small valve on the engine’s intake system that reads the air intake as it comes into the motor. This is controlled by the car’s ECM which uses this information to make adjustments to the air/fuel ratio depending on various inputs such as outside air temperature, intake air temperature, load and various other things. As you accelerate, your car’s engine is receiving a much higher dose of fuel than when at idle and conversely, when you let off the gas pedal, there is a sudden change in this fuel supply as a result of your foot letting off the pedal. When this happens, the job of the idle air control valve is to bring this deceleration down to a slow and smooth idle rather than suddenly cutting off the fuel supply causing the motor to die. When the idle air control valve is not working properly, this cause a disruption in this process resulting in the engine not being able to idle properly. I would recommend having a professional come to your location to diagnose and inspect your vehicle.
Fuel pump engages. Batery good, alternator good volts, jump start helps when wont start. Temp does not matter. Intermittent?
ANSWER : Hello. Thank you for writing in. There are several reasons your vehicle may only start when jump starting. The first and most common is a build up of resistance that is causing you to need a boost of voltage to get the engine started. This may be due to poor battery cables, a bad ground connection, a poor starter solenoid, and a couple of other issues. The first thing you want to do is perform a visual inspection of the starting system. Make sure there is no corrosion build up in the battery cables. You can also check the resistance across these wires and make sure you have a solid connection between components. You then want to make sure the starter solenoid is doing its job. It is responsible for taking the small amount of electricity sent by the ignition and turning it into a huge electrical charge that is strong enough to push over the engine with the help of some gear ratios in its favor. Do some more testing, and stick to the basics before assuming its something seriously complicated.
Saab 9-3 will not always start. Sometimes I have added gas and it started,also took air filter out then replaced and it started,
ANSWER : Hi there. When you have random issues like this, it tends to be caused by a restriction of fuel, air or an inability for the fuel injection system to effectively mix the air and fuel to be burned. This could be due to a clogged fuel filter, dirty air filter, EGR valve, mass air flow sensor or other fuel system component that is dirty. The turbo tends to add an additional five other possible issues to the list. SAAB’s tend to be pretty complex and should be examined by a SAAB specialist, however, it might be beneficial to have one of our mobile mechanics complete a car is hard to start inspection to see if they can pinpoint issues and recommend or complete the repairs needed.
My car won’t start, neither does my auto. Start. Sometime it might start if I jump it sometimes it won’t.
ANSWER : Hi there. There are a number of issues that will make a car hard to start. Everything from the electrical system to the fuel system to the actual starter itself can be the problem. Finding the root cause of a hard starting engine can take some investigation. Ignoring a hard starting issue can further damage the vehicle, which will often result in a more expensive repair. You might want to have a mobile mechanic complete a car is hard to start inspection so they can pinpoint the source of the issues you’re having and recommend the right repairs be completed.
Car won’t turn over. No lights come on when I turn it. Can’t even lock my doorsvor push the seat up or back.
ANSWER : Your probably correct, it sounds as though your battery is done. But it also sounds like you have charging system issues. I’m not sure that fixing your battery and charging system will solve the problem with the car shutting off, but it’s possible that it will and it’s a darned good place to start. By contacting Your Mechanic, you can have a technician come to your home or office to check out your car and help you figure out what to do next.
Hard start, sputtering even idle, sometimes turns off while idle
ANSWER : Hello:
In general, when a vehicle has problems starting initially, it’s usually caused by a restriction in fuel flow or the mixture of air and fuel to create the right volume of vapor to be ignited in the cylinder. This could be caused by a fuel pump that is faulty, however, there are more than a dozen potential other mechanical components that might be dirty, clogged or damaged that cause the same issues. Before you decide to purchase a new fuel pump, you should probably contact one of our mobile mechanics to complete a car is hard to start inspection first. This will allow them to pinpoint the source of your PT Cruisers issues and recommend the right repairs.
