Skip the auto shop - Our mechanics make house calls

Q: Engine swapping on a Subaru

asked by on

I'm interested in engine swap on my Subaru. If it's cold outside, it starts up fine, but if it's hot or the car has been running for a while, it takes multiple times before it turns over. Car runs fine if it starts. The compression is good.

When the car starts cold, it needs extra fuel. That’s just how the cars work. So if you have a normal car that is running perfectly and when you turn the key, the computer sends extra pulse to the fuel injectors so it starts when it is cold.

If your car starts fine when it is cold, but then when it’s hot, it doesn’t start and you’ve got to crank it over. That generally means that the fuel injectors are probably leaking or the fuel pressure regulator’s leaking. Because a hot engine is hard to start if it has too much fuel. It doesn’t need extra fuel. So you probably have a leak in the fuel injection system somewhere. Have the car looked at by a professional so they can locate the leak and make the repairs needed to resolve this issue.

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: Car oil needs to be refilled before oil change is due

Hello. If you are losing oil, it is either leaking or being burned. The causes of burning oil would be faulty piston rings that allow the oil to blow by into the combustion chamber or bad valve guide seals that...

Q: Check engine light

Hello, thank you for writing in. The check engine light illuminates when the vehicle's computer runs tests and detects and issue. The vehicle is constantly running tests on every system in the vehicle. Therefore it is hard to determine which...

Q: Does diesel grade #2 (with more sulfur) clean injectors better than grade #3?

Hello. You should use the number 2 diesel fuel only. The number 3 diesel fuel is not as good as number 2 diesel. The manual is letting you know that you can use the lower grade fuel as a minimum....

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...
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...
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.