Q: Why does my car stall when you press the gas and it tries to go faster than 20 mph? - 1988 Mercury Grand Marquis

asked by on

when

My car has 94576 miles.
My car has an automatic transmission.

Hello. You should start by looking into your vacuum and fuel supply. Both of these will have an adverse effect when pressing on the gas. There are several ways to test for a vacuum leak. The most efficient being with a smoke machine, but there are other methods you can try as well. The fuel pressure is best tested on the fuel line anywhere after the filter, typically at the fuel rail.

Place the gauge in-line and allow the gauge to measure while you run the vehicle. Compare the readings to the manufacturer specifications. You may need to attempt to recreate the symptoms in order to get a proper reading when the issue occurs. Carbon build-up can also cause acceleration issues.

I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the car is stalling and suggest any needed repairs.

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
  1. Home
  2. Questions
  3. Why does my car stall when you press the gas and it tries to go faster than 20 mph? - 1988 Mercury Grand Marquis

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: new battery is draining within 24 hrs, everything checks out ok by mechanic who is still testing more parts

Hey there, It sounds like you may have a case of parasitic draw. This is when a system stays active and slowly draws battery power when the car is shut off. This can also be caused by the charging system...

Q: Is there a way to permanently turn off the rear parking aide on a 2017 Mustang?

If the "speaker" is dedicated to just the park aid (i.e., is not used in other vehicle alarm systems), you can remove the speaker and place a 50 ohm resister to simulate the presence of the speaker, the purpose of...

Q: Truck idling high

Hi there. You may need to have the carburetor adjusted or you have a binding throttle high idle choke linkage. A major vacuum leak can be something that can lead to having a high idling vehicle. A primary cause for...

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.