Skip the auto shop - Our mechanics make house calls

Q: Car jerks at a steady speed.

asked by on

Ok so I have been having issues. My car has been jerking slightly while I'm keeping it at a steady speed. Such as 45 mpg. I have replace the throttle position sensor and the speed sensor on the tranny. Still no good. I don't know what else can cause this. Perhaps could it be a clogged fuel filter or injector!

My car has 170000 miles.
My car has an automatic transmission.

This may be a sign of a dirty or failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this is dirty or faulty, this causes an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. When this is not working properly, you may also notice a strong smell of fuel. I would suggest having a professional from Your Mechanic come to your home to diagnose your mass air flow sensor.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: EVAP. 2001 Pontiac Firebird

The fuel tank has a vent valve that opens when the engine is running, as the pump sucks fuel from the tank and the tank may collapse if a high vacuum is drawn. Usually this code pops up when the...

Q: Fuel not getting to motor

The fuel system on your vehicle is pretty simple. It consists of the fuel pump, lines, filter, pressure regulator and injectors. Either the fuel pump did not get installed correctly, or it was not the problem to begin with. A...

Q: Checking for answers

If you have questions on your vehicle then you can come to this forum to ask your question and get answers. The more detail of the problem you have and as much information on the vehicle year, make, model, engine...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...