2019 ford mustang idle issue?

[Cjxtreme09]

Quick question guys. I've noticed maybe after about 30-40 minutes of driving my stang it does thing where when I come to stop for a few minutes, I notice the rpm needle slightly shakes and my idle is a little rough. What I'm seeing/feeling is it will kind of shake as if it's going to cut off on me. Not a violent shake but it will start shake a little and sounds like it's gonna stall. But it never does. I feel like if I don't figure out problem it probably will. It's like it's gonna run out of gas but I'm usually at half a tank to a full tank so I should be ok on gas. It a weird problem I'm having and I need a little help. Also I know when I took my battery out and put it back my gas mileage to empty had changed. I was on 50 miles til e. But then it told after I reinstalled battery that I have 70 miles til empty. Not sure if that helps. But any suggestions on where to start will be helpful. Thanks!!

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[ORRadtech]

Tons of threads about this. IMRC runners, cam phasers, evap purge valves, vacuum leaks, fuel pressure are all possibilities.
edit; here's one on the first page.
https://www.mustang6g.com/forums/threads/please-just-need-some-help-with-low-rpm-hesitation.206581/

 

[Cjxtreme09]

Ok I've been looking for the vacuum hose. I'm sorry I'm new to this. I've been trying to find a diagram of where it's located. I can't seem to find it. Any idea on where it is?

 

[Cjxtreme09]

Never mind. I found it. It's connected to the purge valve from what I'm seeing

 

[ORRadtech]

That would be one of them. Most cars have several vacuum lines though.

 

[Coyotebawl]

Had the same issue the other day as well . Pretty common problem, but no definite answer to what the root cause is from my searching.

 

[Cjxtreme09]

What about an o2 sensor? I had someone read some codes on the car although I didn't have a check engine light on and it said o2 sensor bank one sensor 1

 

[NGOT8R]

Have you checked intake tube clamps at the tb, and MAF sensor housing? How about cleaning the MAF sensor with the appropriate cleaner?

Are you able to monitor fuel pressure? Just curious as to whether there’s a huge drop below the normal 58 psi when at idle?

Any issues with starting the car when it’s hot (longer crank time)? If so, your fuel pump could be on it’s way out.

How many miles are on the motor? 93 octane fuel or E85? It may not necessarily take high mileage

You can test for flow by disconnecting the line at the rail and cycling the run/stop switch to see if you get fuel flow. Maybe try this as soon as you detect stumbling. Have a few rags handy when you disconnect the fuel line and a container to insert the fuel line into while you cycle the run/stop switch.

You can also check the FPDM to see if it may be malfunctioning. Simply bypass it and go for a 30-40 minute drive like normal and see if the stumbling reappears. See link below for how to bypass FPDM.

https://www.mustang6g.com/forums/threads/2019-bullitt-fuel-pump-driver-module-failure.201965/

 

[Cjxtreme09]

Yeah sometimes after 20-30 minutes when I go to start back up it is a little rough start. Not as strong as the cold start. Cold start it sounds perfect runs smooth. But after 20-30 minutes acts like it's gonna surge or stall on me

 

[Cjxtreme09]

NGOT8R what am I looking for at when I check the intake tub clamps? Guess dirt and debri

 

[NGOT8R]

NGOT8R what am I looking for at when I check the intake tub clamps? Guess dirt and debri

Just make sure they’re tight and not leaking. The MAF sensor can either be removed from the housing and sprayed down with a can of MAF Sensor Cleaner and reinstalled, or just pull the entire housing and clean it. Lastly, make sure the air filter is clean too.

 

[Wolfys11]

Ive seen this in my eco and now my 10k mile gt, it seems to be a common issue, usually a light rev fixes it for the stop duration, i wouldnt look into it too much unless it really bothers you

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