Missfire after clutch replacement /tune

[04lss]

Last friday i got a 93 lund tune and flashed my car. Saturday night i took it for some driving on the nice deserted roads. I decided to see how the launch had changed. I used LC and ended up detonating the dual mass flywheel. Ford somehow warrantied it.

I got the car back today and on the way home the CEL came on. I read the codes: Intermittent multiple cylinder missfire, cylinder 4 missfire, cylinder 7 missfire, missfire in first 1000 rpm. I hadnt felt it missfire, so i cleared the codes to see if they would come back. I can recreate the missfire

Miss-fire process:
Rev the car to somewhere between 3-4k keep it there (in gear) and let off the gas. The CEL light will flash. Shift up to 2-2.5k RPM. The car missfires on gas. Let off the gas for a bit and it stops and goes back to normal.

I flashed the stock tune back on it, same issue.

I know from my experience in the FI world that tunes can increase demand on coilpacks and cause them to fail, but at 5k miles and simple 93 tune that seems implausible.
I suppose its possible that the launch that killed the clutch did something, but i cant see how.
I know they disconnected the battery when the worked on it. I know this is an ignorant question, but could i need to do a crank relearn?


I plan to take the car back to the dealer but with the tune, every time i do that is a gamble. I am hoping there is something simple.

Sponsored

 

[db252]

Try a crank relearn. Certainly won’t hurt and you can rule that out.

 

[CompOrangeFanatic]

Try a crank relearn. Certainly won’t hurt and you can rule that out.

My thoughts exactly.

 

[Cobra Jet]

Anytime a major component is worked on such as removing the transmission for R&R or doing clutch, you must do a crank relearn.

Here’s the Ford info:
https://www.mustang6g.com/forums/th...s-weird-hesitation.125119/page-2#post-2679084

Also there’s many threads about it with members experiences.

 

[AlbertD]

+4 You most likely need a crank relearn. I changed out my clutch and car started misfiring as well. Crank relearn and all the issues went away. It only takes a few seconds to do once the programmer is hooked up.

 

[americanmuscle1776]

Last friday i got a 93 lund tune and flashed my car. Saturday night i took it for some driving on the nice deserted roads. I decided to see how the launch had changed. I used LC and ended up detonating the dual mass flywheel. Ford somehow warrantied it.

I got the car back today and on the way home the CEL came on. I read the codes: Intermittent multiple cylinder missfire, cylinder 4 missfire, cylinder 7 missfire, missfire in first 1000 rpm. I hadnt felt it missfire, so i cleared the codes to see if they would come back. I can recreate the missfire

Miss-fire process:
Rev the car to somewhere between 3-4k keep it there (in gear) and let off the gas. The CEL light will flash. Shift up to 2-2.5k RPM. The car missfires on gas. Let off the gas for a bit and it stops and goes back to normal.

I flashed the stock tune back on it, same issue.

I know from my experience in the FI world that tunes can increase demand on coilpacks and cause them to fail, but at 5k miles and simple 93 tune that seems implausible.
I suppose its possible that the launch that killed the clutch did something, but i cant see how.
I know they disconnected the battery when the worked on it. I know this is an ignorant question, but could i need to do a crank relearn?


I plan to take the car back to the dealer but with the tune, every time i do that is a gamble. I am hoping there is something simple.

What happened with my mustang

60K miles clutch started shuddering a little at first then horribly coming out of 1st and reverse

No matter how much gas you gave it or how quick you let the clutch out, it felt like when a beginner driver is learning to drive stick and stalls the car out—that kind of shuddering.

The ford dealership said it’d take 1 whole month for them to get to the repair on my car and that I’d have to leave the car with them for the entire month.

Obviously, I couldn’t go without a car for that long, so I did some research and found a highly rated private mechanic shop near-ish me.

They diagnosed the problem and installed a brand-new clutch and flywheel (regular ford replacement clutch and flywheel—i.e., not a fancy performance one)

No check engine light initially, within 24 hrs check engine light came on

Went to mechanic. Hooked up scanner #1 (Zurich ZR15S)

I took a picture of the code: P0304 (meaning cylinder misfire in 4th cylinder) to look up later even though mechanic told me not to worry about it.

I looked it up and seemed like it was potentially pretty dangerous

Did some research on ford forums and found discussions about people having had a similar error code (as well as other P03 codes for other cylinder misfires) specifically following clutch and flywheel replacement. These forums mentioned crank relearn and misfire monitor neutral profile correction as potential solution.

Went back within the hour with that limited info and mechanic was initially very hesitant to believe that that was the issue or the solution to the problem—he had never heard of a crank relearn on a mustang, he said.

Understandable: he’s reacting as a doctor would if you came in and started spouting off things you think are wrong with you from having looked at web md—i.e., he’s the professional and people who come in with that type of commentary usually have no idea what they’re talking about.

However, he looked on scanner #2, higher tech looking and didn’t see an option for crank relearn.

Might’ve been a snap on scanner (?), not positive on that, but it definitely looked more like this one:

Mechanic cleared code, said maybe it was a glitch since I wasn’t experiencing any engine misfire.

Went home. No problem till next day, check engine came back on.

Later that night, I actually felt the engine misfire (before I experienced it, I wasn’t sure exactly what that’d feel like, so I wasn’t 100% sure if I’d even be able to recognize it, but once it was actually happening, I knew immediately). The feeling was like a vibrating ratatat when depressing the gas pedal, and when I felt that immediately looked at the check engine light and saw that it had began blinking. That all lasted for about 10 seconds, then it was fine again, though the check engine light was still on.

So, then I was worried, so I did more research: texted mechanic that there was a lot of talk about check engine light problem after clutch and flywheel replacement on mustang forums. So, despite me not being a professional mechanic, asked him to look into it again with the key terms crank relearn/misfire monitor neutral profile correction.

See official ford technical service bulletin (TSB) outlining the problem:

Had car towed to shop just to be safe since I’d experienced an actual engine misfire the nigh before

He hooked up the Snap On scanner above and when I got there, he said he thinks I might be right. Cleared the check engine light, then ran the profile correction.

Link vid to people running that profile correction:





Been 2k+ miles and running like a top now, no check engine light has come back, and the car is running great. Note: for a few hundred miles (about 500 or so) after clutch and flywheel replacement, there was slight shudder (nowhere even near what it was like when I first brought it in) in shifting out of first and reverse. However, have read others experienced the same break in period post clutch and flywheel replacement, and shudder went away completely by 1k miles.

Turns out then whenever transmission is removed from engine, the computers inside the car need to be recalibrated.

See 2:06 for what it looks like when your transmission Is separated from the engine to access the clutch and flywheel for replacement:



Bottom line: super easy fix, just have to know about the “misfire monitor neutral profile correction” process and send them this doc/insist that your mechanic hook his scanner up and run it, even if he’s understandably skeptical because he’s never heard of it.

 

[resto-sauce]

You dont need to take it to mechanic for Misfire Monitor Neutral Profile Connection (MMNPC) reset.
You can download Forscan app. You can get 2 months free trial licence or pay $12 to get 1 year license.


You would need to by the OBDI connector with HS/MS switch
https://www.amazon.com/dp/B083FML519?psc=1&ref=ppx_yo2ov_dt_b_product_details

But the misfire we have didn't go away permanently; it came back
Everything started after installing McLeod RST clutch. (2017 GT 70K miles, ngauge tune)

Now I will try doing another crank relearn (using ngauge) then do another MMNPC reset.

I love the clutch and flywheel very much.
I am resisting the thought of installing heavier stock flywheel.

 

[resto-sauce]

You dont need to take it to mechanic for Misfire Monitor Neutral Profile Connection (MMNPC) reset.
You can download Forscan app. You can get 2 months free trial licence or pay $12 to get 1 year license.


You would need to by the OBDI connector with HS/MS switch
https://www.amazon.com/dp/B083FML519?psc=1&ref=ppx_yo2ov_dt_b_product_details

But the misfire we have didn't go away permanently; it came back
Everything started after installing McLeod RST clutch. (2017 GT 70K miles, ngauge tune)

Now I will try doing another crank relearn (using ngauge) then do another MMNPC reset.

I love the clutch and flywheel very much.
I am resisting the thought of installing heavier stock flywheel.

Misfire Monitor Neutral Profile Connection (MMNPC) reset didnt work.

RST flywheel felt so good, but think I have to go back to stock flywheel.

Sponsored