The reasons why your car can only start after you use the accelerator is because the air-fuel mixture isn't being ignited or the engine isn't getting the right air-fuel ratio for combustion. In other words, either the fuel or air isn't enough for the engine's normal operation.
Crank-no-start problems highlights
- Level of urgency:High
- Can you drive?Obviously, no
- DIY inspection:Possible but complicated
- DIY repair:Mostly,impossible
- Price for repair:$350 - $800
- Common Reasons:No spark, no fuel, no air, battery issues, starter problems, electronics
- Ways to fix:Inspect units that may cause this problem one by one
Finding the Cause of a Car Starting Only After the Gas Pedal Has Been Pressed
You may be able to perform DIY checks for this problem without seeking professional help. So maybe the explanations in this section are all the guidance and motivation you need to proceed. But if you aren't confident in your practical knowledge, then hiring an expert is the best.
Try not to delay before getting to the root of the starting issue. Just pumping your gas to get by without a sense of emergency isn't the right attitude to this situation. You may just be making a minor starting problem worse!
1) Clogged/Blocked Air Filter
A car's air filter is typically tasked with cleaning and filtering the air that goes into your engine to serve the ignition sequence. It ensures that dirt and debris don't accumulate on the passageway that links the air's entrance to the engine. Simply put, your engine is very dependent on the air filter.
Clogging or blockage in the air filter is one of the most common reasons that make vehicles stall. And the only way to get out of such a situation temporarily will be to hit the gas.
The filter experiences partial blockage after a long time of usage, especially if it wasn't changed in time due to negligence. It could be a significant level of obstruction at the beginning of the air intake leading to the engine stalling among other potential problems. But the ultimate consequence will be critical engine damage!
You can actually detect this issue's buildup early by simple observation. A drop in engine power and performance could be noticed when the air-fuel ratio starts getting irregular.
2) Defective Fuel Pump
Fuel pumps drive fuel from the tank to the engine to help in the combustion process. These pumps were mechanically worked in the past. However, they're presently electrically operated on most modern automotive gasoline-powered cars.
The fuel pump is a very small electric motor housed in a sealed compartment that's saddled with the role of pumping fuel. This tiny motor can experience wear after long-term usage, thereby potentially leading to a variety of issues. And one of those problems is the supply of gas to the engine being cut off.
You'll only be able to fix this defect by taking out the worn pump and installing a new one. This is because most fuel pumps are in sealed places, as stated earlier. Simply put, you can't reassemble the old pump after dismantling it. Hence the need to put in a new one is the only way forward.
The swapping process is tasking and will involve disassembling the old pump among other (complex) steps. For example, removing the fuel tank to get to some areas that are hard to get to. Fuel pump changing procedures vary based on vehicle make and model.
3) Dirty or Damaged Fuel Filter
Fuel filters ensure that dirt, debris, or contaminants don't get to the engine. It's essentially the same function as the air filter. And dirt in the fuel filter is as bad as clogging in the air filter. The former can lead to the main issue being discussed as well because it's one of the most crucial components of the fuel line.
A fuel filter requires regular maintenance and routine replacement just like the air filter. You could clean it or soak it in a suitable solvent to dissolve sludge or wash it. And when it's too dirty beyond saving or damaged, a replacement will be in order.
Several issues can be brought about by a dirty or clogged fuel filter-apart from your car not starting. Many hidden issues will keep popping up without you knowing that it's your neglect of the fuel filter that's doing the "damage".
A broken or damaged filter will let in all sorts of unwanted things into the engine which will accumulate and cause problems for the system. It's like a time bomb for critical engine failure. Things can be worse if you've been using low-quality gas or have been driving on a low-level tank occasionally.
Clogging in the fuel line is an uncommon occurrence and you won't have to experience it if a good maintenance culture is practiced. Cold weather may make the accumulated contaminants solidify or bond together and become bigger. So a significant blockage is most likely to occur during such periods.
Resolving the fuel filter clogging issue can be a tedious process. It takes a lot of skill and time. But that's for those that want to save costs. You could easily just replace it to start getting pure fuel into the system again without stress.
Going DIY may be a daunting task for the job of cleaning the filter. But it's not much of a hassle if you want to swap out the filter yourself. Still, the difficulty will depend on the vehicle's make and model. The fuel filters on some gasoline-powered cars have been described as a "nightmare" to change.
What about the accumulated contaminants in the fuel line? That's another story that presents a higher difficulty level. Gasoline lines are so small or narrow that even a single particle can pose significant threats.
4) Compression Failure
Compression errors will start occurring when the lifespan of your car's engine is almost completed. This will lead to the engine burning oil and cause your vehicle's starting problem. The simplest method to implement in solving this issue is to get a trusted professional for the job.
An expert will utilize specialized equipment for cylinder compression evaluation. Apart from this, he or she will be able to perform enough checks to let you know if the engine is beyond saving or not.
5) Mass Air Flow Sensor (MAF) Sensor Failure
The MAF sensor tracks the amount of air that enters the engine's air intake. You can find this unit between the throttle body and the air filter.
This sensor may fail and cause the engine to make do with an inappropriate fuel-air mixture. This will lead to the inability of the engine control module (ECM) to calculate the gasoline supply correctly. And starting difficulties will follow unless you pump the gas pedal. Replace the sensor without delay when it fails.
6) Clogged/Blocked Throttle Body
Recent model-year fuel-injected cars feature an intake system that controls the engine's airflow through the throttle. So you can see that the throttle body is also important for your car to start successfully.
But this unit can also get clogged or blocked, just like the engine's air and fuel filters. Such a condition will cause a restriction of engine airflow and reduce the automobile's performance as time passes. The unburned fuel will then flow into the exhaust system, leading to the vehicle not starting but only cranking.
Maintenance Culture for Avoiding This Starting Issue
Fixing the problem can be satisfying, but that doesn't mean that the issue can't repeat itself. Avoid it by doing the following:
1) Utilizing High-quality Fuel and Replacement Parts
Using substandard replacement parts for the repairs isn't a good idea, even if it's a cost-saving approach. The same goes for low-quality fuel too.
Each part of the vehicle has its own lifespan and buying a low-quality product means that its lifespan will become shorter. The substandard part will be more susceptible to damage or failure. It will also not be as efficient as a standard product.
2) Cleaning with the Right Methods and Cleaning Agents
You can see that most of the issues presented are the results of contaminants or their accumulation. So use efficient (professional) cleaning methods and cleansers to get rid of dirt, debris, sludge, etc.
Conclusion
Routine maintenance can help you prevent all of the causes of your car not starting (but only cranking) mentioned above. Maintenance is way better than having to pay huge amounts that may come with performing repairs or replacing components. Worse still, you may have to replace the whole engine.
The key is not to delay whatever checks or repairs you want to carry out. The more you try to start your car by pushing the gas pedal for the engine to run, the more the situation will deteriorate. And the worst is always the avoidable catastrophic engine failure.
About the authors
The CarAraC research team is composed of seasoned auto mechanics and automotive industry professionals, including individuals with advanced degrees and certifications in their field. Our team members boast prestigious credentials, reflecting their extensive knowledge and skills. These qualifications include: IMI: Institute of the Motor Industry, ASE-Certified Master Automobile Technicians; Coventry University, Graduate of MA in Automotive Journalism; Politecnico di Torino, Italy, MS Automotive Engineering; Ss. Cyril and Methodius University in Skopje, Mechanical University in Skopje; TOC Automotive College; DHA Suffa University, Department of Mechanical Engineering
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