Q: Car jolts while accelerating and won't accelerate from stop.

asked by on

I've been having this problem for a few weeks. My car will jolt on acceleration, and lately when I try to move from a stoplight or after braking, the car doesn't move forward after I release the brake and I have to step on the accelerator really hard to get the car to move. I thought it might be a problem with the fuel injectors, because when the problem first came about I used some fuel injector cleaner and the problem improved and almost went away. Adding some fuel injector cleaner helps slightly now, but not always. My mechanic said it just smelled like old gas, that I should use plus gas for a week or two, and he tuned up my car. My car felt much better for about two days, but now it's back to the hesitation again.

My car has 90000 miles.
My car has an automatic transmission.

Hello. From what you are explaining it sounds like you either have a failing fuel pump or a bad catalytic converter. Both of these issues will cause these symptoms.

I usually start by scanning the computer for codes first to see if there is any indication of a bad sensor. If those are fine then I check the fuel pressure. If the pressure is below specs then the pump needs to be replaced. If it is fine then the converter back pressure needs to be checked to see if it is failing as it will clog the exhaust and keep the engine from building power.

If you plan on having this repaired, consider receiving assistance from a certified mechanic who can come to your home or office to diagnose this lack of power and get your car running normally again.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. Car jolts while accelerating and won't accelerate from stop.

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: How much would a spark plug change be for a 4.6l 99 expedition? And should I change coils too?

Billing question was sent to CS for the cost to replace the spark plugs and the ignition coils on a 1999 Ford Expedition with a V8-4.6L engine.

Q: Code P2562

Hi Davon. Thanks for contacting us today. The P-2562 code is a generic powertrain code related to vehicle speed control and the idle control system. It appears when the turbocharger boost control position sensor circuit has sent a reading to...

Q: Car has rough idle and ticks.

If the engine has low compression on one cylinder it is usually an indication of a damaged valve seat or possibly a bad head gasket. If it is also accompanied by a ticking noise then there may be an issue...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.