Skip the auto shop - Our mechanics make house calls

Q: Vehicle hard to start, but runs well once started.

asked by on

Vehicle hard to start, but once it is started it runs well. It also idles well with no misfires.

A: Hi there, The problem you are having is mos...

Hi there, The problem you are having is most likely due to the fuel pressure not holding it’s static pressure to the injectors. The fuel system needs to hold fuel pressure to the injectors in order for the injector to spray fuel into the engine as soon as you start cranking your engine. If the fuel pressure drops after you shut off your vehicle then the next time you crank your engine the injector will open, but there is no fuel there to inject into the engine and it will take about five seconds of cranking to get the fuel pressure built up enough to start injecting fuel to start the engine. YourMechanic would perform an inspection, they would test the fuel pressure and isolate the problem as being either the fuel pump check valve, regulator or a leaking injector. If it is an injector then you would have a rough running engine until the excess fuel gets burned off. Once tested and the failed component is isolated, then the repair can be done.

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!

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: My heat stopped working, my back brakes need replace, im late on oil change, it clicks at a crawl, service engine soon lite is onI

The check engine light will not illuminate to warn the user for maintenance. The check engine light comes on where there is a problem with the vehicles management system that may result in high emissions like misfires to failed sensors....

Q: I changed the battery in my ford explorer 2013 and the lights and radio work but it won't start. It says to push the brake but it won't work.

Hi there. Check to see if the battery cables are tight. If the cables are tight, then check the brake switch on the brake pedal. It may not be responding to the computer as it could be damaged or shorted....

Q: No power in console

The accessory ports on your 2012 Fusion have both an in-line fuse and primary fuse in the fuse box. However, in most cases like this, the problem is an electrical relay. There are two ways you can resolve this. First,...

Related articles

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.
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.