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・Save up to 30%

Get a quote

What others are asking

Q: Engine siezed

The first thing to do is remove the spark plugs and see if the engine turns over now. You may be hydro-locked from coolant getting in one of the cylinders from a leaking head. If you want to have this...

Q: How do I read the fuel gauge?

The fuel gauge is located on your instrument panel, and displays how much fuel is left in your gas tank. When the fuel gauge displays that you are nearly out of fuel, then you should add gas to your tank...

Q: What is the fuel pump shutoff switch?

Your car is equipped with a fuel pump shutoff switch designed to activate during an accident. This prevents fuel from pumping if the lines or engine has been damaged, preventing a possible vehicle fire. If the engine will turnover but...

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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.