2019 S550 stock clutch replacement, misfire

[aquahd24]

I’ve been trying to chase this problem for well over a few months now. My stock clutch had gave out on me while at the track. I replaced both clutch and flywheel since the mishap. Ever since have had random misfires on start up and cylinders 2,5,6,7. I’ve done a crank relearn and kam reset still no dice. Anything advice and what I should do next?

Sponsored

 

[resto-sauce]

try resetting Misfire Monitor Neutral Profile Connection (MMNPC) reset (using ForScan)


I think its happening because light flywheel makes crankshaft spins too fast and moves the away from the combustion-ready position. If thats the case a new tune would work.

fwiw Mine has 91-93 lund tune.

I am giving up, I about to install stock flywheel.

 

[Cobra Jet]

I’ve been trying to chase this problem for well over a few months now. My stock clutch had gave out on me while at the track. I replaced both clutch and flywheel since the mishap. Ever since have had random misfires on start up and cylinders 2,5,6,7. I’ve done a crank relearn and kam reset still no dice. Anything advice and what I should do next?

I didn’t see you mention it, but have you pulled the crank sensor to inspect it?

- 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

The crank sensor also reads the tone ring, which relays info back to the PCM. If the tone ring is ever so slightly damaged, no matter how many crank relearns are performed or how many new crank sensors are installed, it's not going to solve any problem, because the tone ring would need replacement. To determine if the tone ring was damaged requires removal of the transmission.

See this thread for Tone ring info:
https://www.mustang6g.com/forums/threads/p06e9-dtc-no-start.150022/page-2#post-3066365
See this thread; the first image in it, the round circular toothed object on the floor directly below the engine - that is the Tone Ring. It gets placed onto the back of the crank so the Crank Sensor can read it (also seen in the image):
https://www.mustang6g.com/forums/th...utch-install-and-flywheel-bolt-warning.87130/

—-

Hope some of that is helpful.

 

[Call_Me_Bruce]

If you had your clutch replaced and this has been acting up since, I would get a wiring diagram and figure out where the grounds are for the coils & injectors. I would inspect for a loose ground or possibly a pinched harness. it is a possibility that the harness including the ground may have been disturbed during the clutch repair. You can get a wiring diagram for you car from motorcraft online. I think a 24 hour subscription is $20ish dollars. Punch in your VIN and you get access to all the shop manuals, including wiring diagrams. Get it jacked up, pull the belly cover get a good light and give it a good visual inspection. And to Cobra Jet's post on a bad tone ring, that is an excellent suggestion. If you had a Pico scope and a good wave form you could figure out if the tone ring is bad, but that is next level diagnostics and Pico scopes are not cheap. On on older GM trucks there is a ground on the back of the engine that causes problems with the injectors & coils, especially in salt states. I realize your Mustang is not an older GM truck, but this is where I would start.

 

[resto-sauce]

I guess it really depends on the scenario.

but have you pulled the crank sensor to inspect it?

It makes sense, 100%. The way the previous clutch died in a destructive way. The driver changed the gear at 6K rpm and let the clutch go too early. Kaboom.
First mechanic who replaced the clutch said when they opened it clutch pieces and dust fell on them.
After McLeod RST replacement it needed a relearn, but the relearn could not be done properly probably because the position crank sensor is magnetic and it picked metal dust when clutch was destroyed.
A new tone/pulse ring also great idea, but before that I will try the easier and cheaper replacement; the crank position sensor. Tone ring replacement is a lot of work.

 

[resto-sauce]

Crank position sensor replacement did not work. Still getting P3000, P3003, P3004.
Btw for refresh, the initial incident was getting a new clutch and lighter flywheel after the destruction of the clutch and flywheel which was caused by letting the clutch go too early at high RPM.
Someone suggested to do run a leak down test to check if there is cracked head or bent valve.
Can a messed-up-shifting bend valves?

 

[resto-sauce]

Crank censor replacement did not work.

The third mechanic thought it could be happening because of solenoid and took $1.5K for solenoid replacement. (Then suggested to replace cam gears and chain for $4K, but I don't wanna go that route because I am sure it started after the clutch and the flywheel were destroyed by missed gear at 6500 RPM)

Still misfiring.

Next and final move is to crank pulse/tone ring and load bearing replaced but while transmission is down maybe I should undo the RST clutch and flywheel and go stock.

 

[Cobra Jet]

Out of curiosity, is your timing system still stock as well as the OPG? Or have you had the timing cover off to do any work there such as OPG, VCT’s, etc

Sponsored