HELP. Please read. Surging issues

[Righty697]

Okay so where to begin. I've been having a series of issues with my 2015 GT ( manual) (85,000 miles)
The issues include
●Slight surging,bucking under acceleration and cruising.
● RPMs fluctuate at idle from 400-1000rpm weather it's cold or warmed up
● it's thrown the advance service track code a couple times but then it disappears after the car sits for a while off.
The car is drivable,but it isn't designed to drive like that.
So far I've taken it to a well known ford dealership in North west Indiana. Told them everything I just typed pretty much.
Those mother Fuckers just plugged in there code reader checked everything. Took it for a couple minute test drive and came back and said " car is performing as designed" the fuck it is. Give me some of that shit yall are smoking.
So ford pretty much told me to go fuck myself . So I just took it get a 128 point inspection cause why not. Nothing popped up other than Coolant and brake fluid will need a flush. No biggie right.
I do all the maintenance on this beauty.
She gets oil changes every 5000 miles or less. Never over I'm very good about that.
I'm only gonna list motor maintenance I've done to try and solve this issues.
Did throw a MAF code at one point.
1) replaced Throttle body with oem remanufactured
2) replaced coil packs and plugs
3) replaced maf with an 120$ maf instead of 200+$ oem maf.
4) new air filter.
5) new purge valve.
Car has the same factory clutch from 2015 still.

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[Linkster1666]

IDK. Look for a vacuum leak?

 

[Cobra Jet]

Welcome to the site. We don't need all the name slaying with foul language.... While I get you're upset, it's not necessary in getting a first post out or the point across to us for trying to help you out.

What's the mileage on the car? What mods does it have, any?

Do you have any stored DTC codes or even check for any? If you did check and there were codes, what were they? If you have not, you don't need a fancy code scanner you can do it via this info:

If you have a 2015-2020 with the ANALOG gauge cluster, you should be able to enter the “Engineer Test Mode".
Follow this link:
https://www.mustang6g.com/forums/threads/engineering-test-mode.27581/

If you you have a 2018+ with the DIGITAL cluster, you should be able to access the same test mode found here:
https://www.mustang6g.com/forums/th...n-18-digital-dash-old-way-doesnt-work.115231/

-----
Check your battery cables and posts. Clean the posts and cable ends. The S550 is known to get corroded battery cables (some very bad). There were TSB's sent out through Ford about this issue. If either battery cable is severely corroded, the damage is wicked past the terminal end and cable should be replaced.

-----
Check the connector at the MAF and make sure it's totally secured. Make sure you don't have any breaches along the air intake track, or any cracks damages to the intake. Any such breach before or after the MAF is a vacuum issue and will skew signals for incoming air flow monitoring.
-----

Also to note, if any type of major engine or trans work was ever performed on the car, the car must go through the crank relearn procedure (even if the clutch was replaced). These aren't 1990's cars where things can be taken apart and the car's PCM doesn't react to any major changes. Everything on the S550 is tied by canbus and multiple modules that monitor everything. Here's some info from the forum with how to do crank relearn.

Check the pdf in this linked thread; any time there is major engine work or trans work performed on the S550 5.0, the Dealer Service Tech (or DIYer) is supposed to do a crank relearn procedure.

https://www.mustang6g.com/forums/th...s-weird-hesitation.125119/page-2#post-2679084

Also check this link if you have a n-gauge for crank relearn:
https://www.mustang6g.com/forums/threads/new-clutch-dtc-and-shudders.148583/#post-3035678

Crank relearn with SCTX4:
https://www.mustang6g.com/forums/th...des-codes-and-more-codes.146485/#post-2999715

Crank relearn with HPTuners:


M6G member @Jn2 crank relearn:
https://www.mustang6g.com/forums/threads/sct-crank-relearn-questions-please-help.69190/#post-1586668

---
Here's info for how to do KAM reset too:
https://www.mustang6g.com/forums/threads/kam-reset-magic.148830/#post-3040046

https://www.mustang6g.com/forums/threads/ecu-reset-how-to-do-it.36757/#post-897609

--------

I would start first with the DTC code extraction and troubleshoot from there. Don't throw parts at the car, specially all at once without determining if the issue is air, fuel, spark or sensor related.

If you can't get codes or there are none, check this thread for damage to the intake which affects the IMRC functions. The IMRC design has been problematic since the IMRC intake system first debuted in the 1994 Lincoln MKVIII with the 4.6 DOHC (which was then carried into the 1996 Cobra and beyond). Theres MANY threads on here regarding the intake and IMRC system.
https://www.mustang6g.com/forums/threads/possibly-broken-imrc-shaft.183221/#post-3689879
-----

The other (2) most common Coyote issues that could result in stalls or operational issues:

- VCT solenoids - if the solenoids are not operating properly due to debris or they are failing due to age, they can cause such codes. Quite a few threads on here about these prematurely failing and/or how to diagnose.

This most recent thread, the culprit was the VCT solenoid::
https://www.mustang6g.com/forums/th...s-and-cam-retarded-codes.176734/#post-3571964

Here's (2) more threads for VCT info that I had previously posted in other threads:
https://www.mustang6g.com/forums/threads/2015-2021-s550-5-0’s-ssm-50067-vct’s-again-various-dtc-codes.169419/

https://www.mustang6g.com/forums/threads/p0018-code.123932/

- Crank sensor - failure can be the sensor itself, the harness to it or the pins in the connector. If the crank sensor is failing, it also will throw various misfire DTCs. The only time the crank sensor will throw a specific crank DTC is if the sensor is disconnected or it has completely failed. Many have found even with a generic misfire P0300, that the issue was related to the crank sensor. These sensors do not last forever due to their location and under hood heat cycles.
Check this thread:
https://www.mustang6g.com/forums/threads/misfire-at-high-rpm.174380/#post-3531453

AND this one:
https://www.mustang6g.com/forums/th...e-sensor-tone-ring.156234/page-2#post-3197692

That should get you started. Report back your findings.

 

[Righty697]

IDK. Look for a vacuum leak?

Yes....tried. nothing.

 

[Righty697]

Welcome to the site. We don't need all the name slaying with foul language.... While I get you're upset, it's not necessary in getting a first post out or the point across to us for trying to help you out.

What's the mileage on the car? What mods does it have, any?

Do you have any stored DTC codes or even check for any? If you did check and there were codes, what were they? If you have not, you don't need a fancy code scanner you can do it via this info:

If you have a 2015-2020 with the ANALOG gauge cluster, you should be able to enter the “Engineer Test Mode".
Follow this link:
https://www.mustang6g.com/forums/threads/engineering-test-mode.27581/

If you you have a 2018+ with the DIGITAL cluster, you should be able to access the same test mode found here:
https://www.mustang6g.com/forums/th...n-18-digital-dash-old-way-doesnt-work.115231/

-----
Check your battery cables and posts. Clean the posts and cable ends. The S550 is known to get corroded battery cables (some very bad). There were TSB's sent out through Ford about this issue. If either battery cable is severely corroded, the damage is wicked past the terminal end and cable should be replaced.

-----
Check the connector at the MAF and make sure it's totally secured. Make sure you don't have any breaches along the air intake track, or any cracks damages to the intake. Any such breach before or after the MAF is a vacuum issue and will skew signals for incoming air flow monitoring.
-----

Also to note, if any type of major engine or trans work was ever performed on the car, the car must go through the crank relearn procedure (even if the clutch was replaced). These aren't 1990's cars where things can be taken apart and the car's PCM doesn't react to any major changes. Everything on the S550 is tied by canbus and multiple modules that monitor everything. Here's some info from the forum with how to do crank relearn.

Check the pdf in this linked thread; any time there is major engine work or trans work performed on the S550 5.0, the Dealer Service Tech (or DIYer) is supposed to do a crank relearn procedure.

https://www.mustang6g.com/forums/th...s-weird-hesitation.125119/page-2#post-2679084

Also check this link if you have a n-gauge for crank relearn:
https://www.mustang6g.com/forums/threads/new-clutch-dtc-and-shudders.148583/#post-3035678

Crank relearn with SCTX4:
https://www.mustang6g.com/forums/th...des-codes-and-more-codes.146485/#post-2999715

Crank relearn with HPTuners:


M6G member @Jn2 crank relearn:
https://www.mustang6g.com/forums/threads/sct-crank-relearn-questions-please-help.69190/#post-1586668

---
Here's info for how to do KAM reset too:
https://www.mustang6g.com/forums/threads/kam-reset-magic.148830/#post-3040046

https://www.mustang6g.com/forums/threads/ecu-reset-how-to-do-it.36757/#post-897609

--------

I would start first with the DTC code extraction and troubleshoot from there. Don't throw parts at the car, specially all at once without determining if the issue is air, fuel, spark or sensor related.

If you can't get codes or there are none, check this thread for damage to the intake which affects the IMRC functions. The IMRC design has been problematic since the IMRC intake system first debuted in the 1994 Lincoln MKVIII with the 4.6 DOHC (which was then carried into the 1996 Cobra and beyond). Theres MANY threads on here regarding the intake and IMRC system.
https://www.mustang6g.com/forums/threads/possibly-broken-imrc-shaft.183221/#post-3689879
-----

The other (2) most common Coyote issues that could result in stalls or operational issues:

- VCT solenoids - if the solenoids are not operating properly due to debris or they are failing due to age, they can cause such codes. Quite a few threads on here about these prematurely failing and/or how to diagnose.

This most recent thread, the culprit was the VCT solenoid::
https://www.mustang6g.com/forums/th...s-and-cam-retarded-codes.176734/#post-3571964

Here's (2) more threads for VCT info that I had previously posted in other threads:
https://www.mustang6g.com/forums/threads/2015-2021-s550-5-0’s-ssm-50067-vct’s-again-various-dtc-codes.169419/

https://www.mustang6g.com/forums/threads/p0018-code.123932/

- Crank sensor - failure can be the sensor itself, the harness to it or the pins in the connector. If the crank sensor is failing, it also will throw various misfire DTCs. The only time the crank sensor will throw a specific crank DTC is if the sensor is disconnected or it has completely failed. Many have found even with a generic misfire P0300, that the issue was related to the crank sensor. These sensors do not last forever due to their location and under hood heat cycles.
Check this thread:
https://www.mustang6g.com/forums/threads/misfire-at-high-rpm.174380/#post-3531453

AND this one:
https://www.mustang6g.com/forums/th...e-sensor-tone-ring.156234/page-2#post-3197692

That should get you started. Report back your findings.

Got it no more cussing or on dealerships that failed to do their job and just take my money.
Thank you I appreciate the lengthy post. I will look into these things.

 

[WildHorse]

Loosen the TB bolts (do not remove), retighten according to the factory specs (very important) in a crisscross pattern. You're welcome.

 

[Righty697]

Update!!!! Problem solved!!!!!!
So if you were following you know I've been having issues ( read previous posts).
Took the car to my dyno tuner I used for my ls1 gto. Amazing shop located in NWI. Highly recommend them. Second time being there with two different vehicles. (Frazz Mobile Dyno)
Dropped off the car. Tuner gets to my stang finally. Well it was throwing a wrench light. Immediately after him starting it. ( hasn't thrown any lights in a while now). Threw wrench light and engine code for the maf. Mind you I just replaced the maf. Replaced everything matter in fact.
Well come to find out when the car is sitting outside a good amount of water drips through the hood vent right onto the roush air filter and then when you'd start the car. The maf would get soaked and wig out causing a wrench light and engine light to come on.

 

[Righty697]

Also by the way.
Made 391 whp on stock tune with these two mods on it. No tuning yet.
Mods
1)roush CAI ( 85mm insert)
2) roush axle back.
3) 93 octane
After the final run it put down 428whp. Did take out the 85mm insert so it is now a 105mm diameter inlet tube.
First and last run was done in the same day.
There's your education for the day.
I'm happy with a 37whp bump. It's just a daily not a race car.

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