Down on power/misfiring

[ElAviator72]

Hi,

took the car into the stealership this morning, because my car seems to have developed a misfire since yesterday.

Idle is sometimes smooth, sometimes very rough. Although the computer didn't throw any codes, the tech noted lots of misfires across all cylinders. They replaced the plugs, however the old plugs look pretty clean :doh:

Where you feel it is on the high end. 5,000 rpm, and no one's home (even worse than the Ecoboost normally is). You can feel the engine stumbling up there.

They turned the car loose, saying "there's nothing else we can do". The idle sounds rumbly when it's acting up...

I'm definitely needing more go pedal to get the car going from a stop. It feels like something is dragging on the engine, like the A/C compressor is going out. However, that's not the issue. I thought my evap core had finally developed a leak, but this morning, it was doing this on a cold start, with the A/C turned off.

It almost feels like a vacuum leak...

100% stock.

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[Redcruzer]

Same or similar issues have been reported to have been eliminated by replacing the fuel sensor in the post below. Might be worth a shot...

 

[ElAviator72]

I did a shot in the dark, and ran some Chevron Techron Super Concentrate injector cleaner through the engine. Things are much better, but not quite 100%. Seems like every drive is slowly improving things...I can't believe my injectors could get so clogged on their own! I've always used Premium since new, and have never filled up at a station that's not top tier. I used to be a little more diligent about running injector cleaner through the engine, but I got a little lapse on that lately...I'll keep you guys posted if the car doesn't return to 100%

 

[lizardrko]

Theres always something else they can do, they just dont want to actually look. The dealer depends so much on codes telling them what the problem is they forgot how to actually diagnose issues themselves. Take it back, show them the problem, go straight to the service manager, if he says to F off, go to his boss. You could go to a different dealer, but why let this one get away with being lazy

 

[ElAviator72]

Theres always something else they can do, they just dont want to actually look. The dealer depends so much on codes telling them what the problem is they forgot how to actually diagnose issues themselves. Take it back, show them the problem, go straight to the service manager, if he says to F off, go to his boss. You could go to a different dealer, but why let this one get away with being lazy

Funny thing is, I did take it to a different dealer (because the dealer I bought the car at/normally have it service at) was booked out until tomorrow. I took it to the nearest Ford dealer, and they almost didn't get me in because I was unscheduled, and then the tech only had a 1 hour window to look at it. I was charged $273 for it ($125 diagnostic fee + cost for plug change). Seems like that should have gone in under the power train warranty (I'm at 45k miles...) addle:

 

[ElAviator72]

Anyone know if there's a fuel filter in our cars?

Still having minor issues here and there...

 

[lisandra]

Anyone know if there's a fuel filter in our cars?

Still having minor issues here and there...

Did you change tbe sensor?

 

[ElAviator72]

Did you change tbe sensor?

Not yet. I'm thinking I have fuel delivery issues here. Most noticeable at high RPM with heavy throttle, and while warming up...

Still wondering if the car has a fuel filter, or if it's just got an effin' screen in the LPFP to get clogged up like many modern cars do.

 

[Ronstar]

Not yet. I'm thinking I have fuel delivery issues here. Most noticeable at high RPM with heavy throttle, and while warming up...

Still wondering if the car has a fuel filter, or if it's just got an effin' screen in the LPFP to get clogged up like many modern cars do.

The Senor is a FUEL pressure sensor, hence your fuel delivery statement.

 

[ElAviator72]

The Senor is a FUEL pressure sensor, hence your fuel delivery statement.

Until I have proof that that's the problem, I want to know what the other choke points in the fuel delivery system are. The fuel filter is an obvious next choice...

 

[Rod Schneider]

There isn’t an external fuel filter on these cars. Any filter will be part of the fuel pump module in the tank. The pressure sensor that has been mentioned has gotten a reputation for causing problems similar to what you are experiencing. It’s around $30 or so, and is typically a ten minute job to replace. If it was mine, I’d try the sensor first. Just my humble opinion..........

 

[ElAviator72]

Ok I changed the LPFP sensor...it passed a test drive (including full throttle in second gear to redline). So far so good..

 

[nv6g]

There's a post with same exact problem the flywheel was replaced for rattling or vibration that affects the knock sensors, I'm having the same problem, i replaced the lps but didn't work, i hope it's not a flywheel.

 

[ElAviator72]

Mine was definitely the LPFS

 

[7thStang]

Just did a service on mine. It’s been a little rough running until full warmed up. I decided from what I was read the intake valves are carboning up. So I bought the Seafoam upper valve treatment for DI engines. Followed all the directions, let it heat soak for 45 minutes, then took the car for a ride. Smoke smoke smoke. After the 4th pull it cleared out. I will say the car now idles great, super smooth and is pulling like a freight train. Give that a try. $10.00 at Walmart.

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