Q: Difficult startup, chugging and rough revving

asked by on

My car has difficulty starting. The first time I try to turn it up, it starts pretty quickly. But, during the day, the startup becomes difficult. If I go somewhere for a while and go back to my car and try to turn it on, it has troubles starting. At very low RPMs, it can start with a lot of chugging. Occasionally, when it wouldn't turn on at all, I would give it gas and it would start revving up roughly as I turn the key, keeping my foot on the gas pedal. At that point, I cannot let go off the gas so as not to let it turn off completely. I go to RPMs as high as 2500 for a few minutes. Then, the car would idle and can run normally. While this is happening, the gasoline can be smelt. Also, there is white residue from the exhaust. What do you think could be the problem? Is this serious? Thank you.

Hello. If the engine is having trouble starting after it has ran for a while and you are getting the smell of fuel, then it may be a failing fuel injector or an issue with a bad sensor. Most of the time this is caused by a bad crank position sensor.

When this sensor stops reading, the engine will not start because the computer cannot see an engine RPM reading. I would start installing a scan tool to see if the crank sensor is reading and to see if the coolant temperature sensor is reading correctly. If not, then it needs to be replaced. If it is fine then the fuel system needs to be checked for leakage. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose car’s rough starting issue.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Difficult startup, chugging and rough revving

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: Q: engine revs up and down when in park

The idle is controlled by the idle air control valve and if it cannot keep the engine idling it will keep trying to rev the engine up to compensate. A vacuum leak, sensor that has failed, or an EGR system...

Q: Car makes a loud grinding noise when I try to start it, would this be the starter or timing chain?

You should try and turn the engine manually on front of crankshaft pulley to see if engine is seized. If engine turns over by hand then problem will most likely be the starter. If you cannot turn motor then it...

Q: Why is my engine making a knocking noise.1997 Saturn SL2

Hello. If you know that the timing chain is off then the engine should not run. If the timing is correct but the chain is loose due to other issues then that may be the knocking noise that you are...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...