Q: Hesitate on hard acceleration - 2002 Volkswagen Beetle

asked by on October 30, 2016

When accelerating in to each gear car acts like it wants to go faster then bogs down. In each gear it does this. I have changed the ignition coils and spark plugs also I have changed the air filter and cleaned the mass air flow sensor. It acts like its starving for air when accelerating, but driving slow it's fine.

My car has 186000 miles.

Hi there. Check for exhaust restriction and related to that condition of the oxygen sensors (bad sensors can cause catalytic converter plugging).

Another possibility is fuel starvation so the output of the fuel pump has to be tested (pressure and volume) and the fuel filter should probably be changed in any event as preventive maintenance. Check fuel pressure before and after changing filter because in the event filter is plugged, as that will give you additional diagnostic info.

It is also possible to have plugged or malfunctioning fuel injectors. There are some tests of the fuel injectors that can be done on vehicle but it would be most helpful to check secondary voltage patterns on each cylinder on an oscilloscope. That would reveal, in detail, what is going on with the engine. Other easy to check possibilities are vacuum leaks and engine timing advance function. If you need to have this inspected, a certified professional from YourMechanic can come to your car’s location to diagnose the hesitation on acceleration so that this is correctly addressed.

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

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

I own a 2002 Pontiac Grand Am. My alternator went out, had it replaced. Now my car has a hard shift and the trac off light is on??

You will need to have the computer scanned for additional stored codes for the traction control and may need to have the throttle control relearned to have the vehicle shift correct.

When I rev it it has a hard time.

This is tough to diagnose without more info, however it could be potentially some things like a faulty mass air flow sensor or throttle position sensor. Either of these two parts will have a negative impact on fuel/air flow which...

VW 2007 GTI code c342d

It sounds like the check engine light may be eliminated on your vehicle. I would recommend having your vehicle inspected by a qualified professional to determine the exact cause of the check engine light. Consider YourMechanic as inspection such as...

Related articles

How Car Acceleration Works
Going from 0 to 60 mainly involves the throttle, engine, differential, and tires of a car. How fast it takes depends on the features of these parts.
2012 Volkswagen Jetta vs. 2012 Subaru Forester: Which One Should I Buy?
Mid-size sedans are the realm of small families or commuters who want a slightly larger vehicle than a subcompact or compact car, yet don’t want to fully give up their good gas mileage. The sedan offers more comfort and space...
Industry News for Automotive Techs: October 1-7
Wireless electric car charging, VW diesel scandal payouts, 3D-printed car technology, new Cardone car parts, and high September auto sales.