Skip the auto shop - Our mechanics make house calls

Q: Car only starts when I pump the gas pedal.

asked by on

I replaced the throttle body and now the car will only start when I pump the gas pedal. What do I need to have fixed?

From this description it seems that there could be separate issues happening to your Mitsubishi Eclipse. The three most common reasons I see for a car unable to start without pushing the gas pedal include; the throttle body gasket may have been installed incorrectly, the idle speed control screw needs to be adjusted and finally the throttle position sensor may need to be adjusted.

Every car may be made up of the same parts but they all install and work slightly differently. Sometimes parts aren’t ready to install right out of the box so it is necessary to make certain vital adjustments to the part, in order to have the throttle body do its job properly. If this is the case, a trained professional can easily diagnose this concern on your car and determine if this is indeed the problem and will be able to make the adjustments necessary. While they are doing this, they can also inspect the idle speed control screw. The engine will need to be running, allowing the screw to be adjusted to run at the specified RPMs for that vehicle. Finally, with the throttle position sensor, a certified mechanic can adjust it by using the manufacture specs, it needs to be installed and clocked (turned a specific way) then a voltage meter is used to check the signal voltage (signal voltage is 5v and as you step on the gas pedal the voltage will vary from 1.5 up to 4.5 volts to tell the computer where the position of the throttle is and use his information along with other sensors to determine how much air and fuel are put in the engine) to ensure that the voltage specs are in the proper range.

As you can see, it is important to have a certified mechanic to look over this problem so they can diagnose which part may be failing and get you back on the road safely.

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!
  1. Home
  2. Questions
  3. Car only starts when I pump the gas pedal.

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: Engine leaking oil and making noise

Hi. The common components on any given vehicle that produce oil leaks are the valve cover gaskets and the oil pan gasket. The leaks will usually occur on vehicles above 80,000 miles but can occur as low as 50,000 miles....

Q: My car stalled while driving and will not start.

Hi there. Do any warning lights come on when turning the key? If not, then the battery is discharged. If they do, then there are other possible causes to your no start condition that require proper inspections to diagnose. A...

Q: My key will not turn, no problems before.

Try to move the key in and out slightly while turning to see if it will turn. Try to turn the wheel in the same direction the wheels are turning to relieve pressure off of ignition while turning the key....

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...
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.