So as of recently my truck started stuttering, acting as if it was trying to turn off. All while at red lights or stop sign. But If I'm driving no issues. I noticed that the truck would shake and drop below 1000 rpms. Took it to my mechanic swapped out with all new oem coils. Also maf sensor was replaced. Well it just started doing this again. Any pointers on what to look at?Btw my truck has 158k on body 105k on motor with new timing chain, tensioners, can phasers and everything else needed to the the job. New cam position sensor, new plugs done as well when the timing job was done. As of today i went and cleaned out the throttle body and did the relearn process. Thought this would take care of it, but it didnt.


In this video scroll to 30 seconds to view how my truck acts at a stop light.
https://youtu.be/NpD9llNcOJM?si=nF_BT61ouqhOH90D


Stutters are red light (scroll to 30 seconds)https://youtu.be/phnaTgQmA0k?si=wrlQXgqGKD3Ut57L

Truck while parked
https://youtu.be/Se_OMJpggpU?si=cCOQtlXxgvdu4jN6

 

Do you know if your mechanic has access to a good scan tool?

What we would like to see are the fuel trim values and if you can get them , post them here, thanks.

Based on what we see could help offer a useful suggestion otherwise we would be guessing and that can get expensive.

 

Hanky, I do believe he does have access to it. Once I can get it I will submit. I had a scanner adapter that would be able to read it by forscan. Unfortunately I can't find it. I did order another one and I have a better chance of getting the info faster than getting to the mechanic as they are currently busy.

 

You said MAF replaced, make sure to initiate a relearn.
While waiting at a traffic light, shift your truck to neutral, and pay attention to the RPM does it go higher like from 500 to 800? Do the same while driving and see the RPM difference. It could be a sign of bad speed sensor.
Imagine when driving a stick and you are on 2nd gear while coming to a stop sign and you are too lazy to make full stop and keep your gear in 2nd, you have to rev or too low RPM can cause your car to stall.
On automatic tranny it relies on the speed sensor signal to determine which gear to shift to.
Just a possibility you can look into.

 

Heiki, does it make a difference if the maf sensor was replaced well over a month ago? My issue comes and goes which it the weird part about. For days it'll work fine and days were it acts up.

 

If it was the issue with MAF it can take a few months to get more noticeable symptoms and it can get worse and worse from rough idling to engine sputtering to stalling.
If I were you I wouldn't bother to buy the MAF cleaner like CRC brand. There is no such thing on earth that a MAF cleaner can fix a bad MAF. The cleaner is for maintenance only, like you clean it twice a year regardless of its condition.
Just wait for your FORScan we'll see.
I will try to get you some diagrams and instructions on how to test your speed sensor when I get home.

 

Heiko,

Thank you so much. Point taken on not cleaning the maf sensor. I may have to call my mechanic and ask if oem was used just as i instructed to order as ive learned to use oem for electronics. Learned from my 13 Taurus.

But as soon as i get the fuel trims ill post them.

 

Driveability concerns so here's Chart 1 and 8.






Do you need to see any other chart? Which pinpoint test do you need.