Jeep starts then dies right away? This will undoubtedly be frustrating for you, but how can one avoid it?
Several problems could be causing this issue. If you are lucky, you might fix this problem without using special tools. But it could also be due to a mechanical failure that is costly to repair.
Here are the possible causes.
Table of Contents
Poor Battery Connection
The engine needs current from a battery to function as intended. This is possible only if there is a stable connection. But if the connection is loose, then engine operation might become unreliable. This could be one of the possible reasons why the engine is starting up but shutting down soon after.
To determine if this is the possible cause, you need to look at the battery closely. In particular, you need to check the terminals. Are they corroded? Are the cables damaged or in poor condition?
You can use WD-40 or some other degreaser to clean up grubby battery terminals. If the terminals have collected dirt, then cleaning it off using a degreaser could do the trick.
However, if the problem persists, then you think about using another battery. Or you could try testing this battery on another vehicle (that works fine) to find out if it is a battery issue. If the battery is the problem, you can relax knowing that battery replacements are cheaper than replacing many other parts.
So checking out the battery and ensuring that it is functioning properly is a good starting point.
Fuel Pump Problems
If the battery is fine, then you should inspect the fuel pump. The main function of a fuel pump is to take gas from the fuel tank and inject it into the engine at the right rate. So if the fuel pump has malfunctioned, the engine won’t be able to run properly.
However, you can do little about a defective fuel pump apart from letting a good mechanic take over.
Removing the fuel pump is not recommended. It could spill gasoline which is hazardous.
If the fuel pump is leaking or has some other problem, the best thing to do is to take your vehicle to a mechanic.
As a part of regular maintenance, make sure that you replace the filter at recommended intervals to prevent blocked fuel flow. The filter needs replacement when the vehicle has been driven between 40,000 miles and 80,000 miles in general. Check with the manufacturer manual to find out exactly when you should change the filter.
Replacing the filter with a clean new one is not that hard, so it is something that you might do yourself.
However, you should be very careful about spilled fuel. So you should know about the process. If you have any doubt, take no chances and talk to a mechanic to get the job done safely.
Fuel Injection Sensor
The fuel injection sensor communicates the fuel remaining in the tank to the vehicle computer. If this sensor has malfunctioned, then the engine control unit (ECU) will not be able to send fuel at the right flow rate. This could mean too much or too little gas for the engine, both of which are detrimental.
Once more, you will have to hand over this problem to professionals to deal with complex parts correctly.
OBD2 scanners are useful for diagnosing problems with electronic parts. If you want to find out what is causing the problem, then you can buy one such scanner from an auto store for a relatively low price. As a first step, your mechanic will use the OBD2 scanner to get the error code that will diagnose the problem.
Ignition Problem
The engine depends on the spark plug to generate sparks at precisely timed intervals to be combustion of the fuel/air mixture inside the cylinder. Problems with ignition are a frequent cause of the engine stalling soon after starting.
If you know how it’s done, you can try taking out the spark plug to clean off any dirt if it is there. However, you will need to be patient to access the spark plugs. Before you remove the spark plugs, make sure that you take a close look at the cables connecting them to the electric circuit of your vehicle. These cables should not be worn or frayed. Take a close look in particular at the connection.
If the issue is not remediated by cleaning up spark plugs or obvious damage to your spark plugs, you will have to replace them. Depending on the year of manufacture and make of your Jeep, a spark plug set for Jeep will cost around $30 to $60. if the cables connecting the spark plugs are damaged, then you can get them replaced for a relatively low price.
Engine Control Unit Issue
If your engine sensors are working as intended, then things can go wrong if the ECU malfunctions. That is because the ECU utilizes information that your engine sensors are producing. If the ECU cannot process the information correctly, it will not provide the right fuel rate for the engine to work smoothly. In addition, a faulty ECU may be unable to provide crucial signals to different engine parts, which can cause the engine to malfunction and shut down.
The OBD2 scanner can diagnose the ECU problems if it is causing the issue. If a scanner is available, then you can use it to read the error code that the vehicle is providing. However, if you don’t want to do it, then you can always take the vehicle to a mechanic so that experts can scan it.
Malfunctioning Alarm System
The alarm system could be behind this problem. If the electronic anti-theft system thinks the vehicle is being stolen, it will cut off the fuel flow. The problem is that a false alarm can be triggered due to a few reasons. Faulty keys are a common cause of this issue.
There are chips within car keys these days which inform the vehicle computer that you are the actual owner who can start the vehicle. If the chip is malfunctioning, then this problem can arise.
Likewise, if the chip scanner within the vehicle is faulty, it won’t read your key chip properly and identify it as valid. This can cause the anti-theft system to be activated, due to which the engine will shut down.
If you think that this is a possible cause, then you should let a mechanic check your vehicle.
Low Fuel Pressure
Fuel injection engines require the right fuel pressure to keep running smoothly. If there is not enough fuel pressure, then the engine will cease running. There are various reasons for insufficient fuel pressure.
Most often, it is due to a faulty fuel pump. The fuel pump may be providing sufficient pressure during engine start, but not enough to continuously run the engine.
The gas tank is where the fuel pump is located. However, an engine port lets you measure the fuel pressure using a gauge that can be obtained from an auto store. You can use this instrument to check out the fuel pressure. You should take the key towards the on position with the gauge in position. Check the fuel pressure. Then you should start up the engine.
Is there an immediate drop in fuel pressure? Does it fall back to 0? If it goes down to zero and won’t come back up again, there could be a problem with the fuel pump’s relay. If the pressure goes down, the engine shuts down, and the fuel pressure rises again, it could be a bad fuel filter or an issue with the fuel pump.
A good mechanic will use a scanner to determine the voltage across the fuel pump’s relay. The voltage should be constant.
MAF Sensor
MAF stands for “mass airflow”. As the name implies, the function of the MAF sensor is to measure how much air is entering the engine. It is located between the throttle and the air filter. This is a vital component for measuring the air/fuel ratio.
If the mass airflow sensor malfunctions, then as you may have guessed, the engine will shut down. Check the wiring harness to confirm that it is properly connected. Take a close look at the whole wire to find any sign of burning or damage.
If the mass airflow sensor is not working properly, the engine could run erratically or shut down.
The mass airflow sensor determines the air density at the manifold intake. It supplies this value to ECU, which then uses values obtained from other sensors to control the flow of fuel into the cylinder.
If you find out that a new mass airflow sensor is required, they are fairly inexpensive. You can replace them quite quickly since they are found easily beside the airbox.
Bottom Line
You can connect a code scanner to find the trouble code. This will tell you what’s going wrong with your vehicle. However, you should bear in mind that the aforementioned reasons are the most common causes, and they are likely behind the problem
Take your vehicle to a mechanic to confirm the problem.