Fuel cutting

[porter c]

I’ve recently been having issues with fuel.
After filling up it acts as if it wanting to stall out, and on startup regardless of filling up or not it takes a little longer to crank.
2 weeks ago i did spark plugs and valve cover gasket just because i needed them anyway and I replaced the purge valve yesterday and now today fuel is cut at about 3k rpm’s if i’m doing a pull, and is running a little rough.
Any thoughts or comments are appreciated


Mods:
Cobb intercooler
JNP catless DP
MBRP catback
accessport v3
Stratified flash tune on 91.

 

[porter c]

Edit: 2016 Fiesta ST
155,000 miles

 

[TyphoonFiST]

Possible LPFS= Low Pressure Fuel Sensor On the feed line near the firewall wall. I did a mini DIY here on the forum.

 

[Zeille]

Possible LPFS= Low Pressure Fuel Sensor On the feed line near the firewall wall. I did a mini DIY here on the forum.

I second this, my car had this exact same issue and it was the LPFS. Monitor your Low FP actual at idle & driving - you want to see between 75-90 at idle, and mine was 50-60 idle. My car would also act like it went into limp mode in the middle of driving - thankfully it happened in the city and not on the freeway. No possible acceleration & no boost for a few seconds, but it went off and went back on as a switch.

 

[porter c]

Possible LPFS= Low Pressure Fuel Sensor On the feed line near the firewall wall. I did a mini DIY here on the forum.

I replaced the sensor today with motorcraft aswell as put in the entire purge valve line that goes into the intake manifold. I had one from oreillys and decided to just re replace it with motorcraft. I reset the KAM on my AP, took it for a drive and it had a small stutter on the first pull like it did before. parked it for a few hours cus I was upset that it didn’t fix it haha. Then a few hours later I drove it home and it drove perfectly fine no issues. Not sure if it was an automated stutter for the computers just cutting fuel in case it was still an issue or what. It’s been fine the rest of the night though. Planning on cleaning injectors soon anyway.
Sorry if this didn’t make sense but thankyou for your pointers haha.

 

[porter c]

I second this, my car had this exact same issue and it was the LPFS. Monitor your Low FP actual at idle & driving - you want to see between 75-90 at idle, and mine was 50-60 idle. My car would also act like it went into limp mode in the middle of driving - thankfully it happened in the city and not on the freeway. No possible acceleration & no boost for a few seconds, but it went off and went back on as a switch.

Thankyou!!

 

[Zeille]

Thankyou!!

After we replaced my sensor, my car still read low on the low FP & we were worried the actual fuel pump was broken.
However, resetting ECU learning allowed the car to start fresh & it ran fine afterwards.