Cutting out while driving

NATHAN 311

MEMBER
2003 FORD EXPEDITION
5.4L
V8
4WD
AUTOMATIC
230,000 MILES

The car started cutting out while driving. The check engine light came on so I took it and had AutoZone check it with their code reader it said I had a misfire so I changed the plugs. The plugs have never been changed until now. After I change the plugs it was still cutting out and the check engine light came back on I took it again to have them put their code reader on it and it said EGR valve I replaced it. The car will idle smooth when you take off it is still cutting out. Any help would be greatly appreciated thank you in advance.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Welcome to 2CarPros.

Has the check engine light come back on since the EGR was replaced? When it cuts out, does it stall or does it feel more like a misfire? This can be the result of many different things. Even a bad fuel injector or fuel pump. We need to try and narrow it down. Let me know if it stalls completely if it will start right back up. Also, if you could, let me know if fuel pressure was tested, fuel filter was replaced, injectors were checked, if the engine has the normal amount of power when it is running. Anything you can think of may be helpful. Here are a couple links you may find interesting:

https://www.2carpros.com/articles/engine-stalls

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Let me know.

Joe

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Saturday, February 16th, 2019 AT 8:45 PM

NATHAN 311

MEMBER
2 POSTS

The check engine light did come back on after the EGR valve has changed. I replaced a coil pack that headache rack where the wiring plugs in. The check engine light is now off and has remained off. When the vehicle is running sitting in idle it has a little putter to it. When you are driving it down the road it wants to go but it's like hesitating. It might pick up speed for a few seconds then it starts cutting out and the check engine light will not come back on. The fuel pressure has not been checked I have done no other work to it.

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Sunday, February 17th, 2019 AT 12:09 AM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Welcome back:
Since the light isn't on, I recommend checking two different things. First, confirm the fuel pressure is within the manufacturer's specs and the fuel pressure regulator is working correctly. Here is a link that shows in general how to check pressure and the regulator:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the manufacturer's specs for pressure:

Item .................... Specification

Key on, engine off .................... 379 kPa (55 psi)
Engine running .................... 379 kPa (55 psi)

Now, if that checks out good, my next suspect is that one of the catalytic converters is partially plugged. Take a look through these links:

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

https://www.2carpros.com/articles/catalytic-converter-replacement

Do these things and let me know the results. The more I think about it, I'm questioning the converter. Since there is a loss of power, that could be the issue. Also, often times when the converter is plugged, it will glow red hot after running for awhile. You may want to check for that, too.

I will watch for your reply.

Joe

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Sunday, February 17th, 2019 AT 4:37 PM