Cylinder Misfire

[TerryBoss302]

Hello group.
I could use some help. I bought Rick's Boss 302 and love the car. Last time on the track the engine light came on. According to the computer, it had a cylinder misfire. I felt nothing and the car ran fine. We cleared it, I went back out on the track and a few minutes in I got the message again.

We packed up and left and I dropped the car off at the local Ford dealer.

It has been in there over a month and they can not figure it out. They say the cylinder is not misfiring but something is causing the error on the computer.

Previous to this, they had just replaced the transmission for a gear going out.

They have replaced a sensor next to the clutch and now Ford and the dealer says they will not proceed without me paying for the stock clutch to go back in. I have no idea how a clutch would cause this.

The powertrain was still in warranty when I dropped it off but they are saying what they are working on is not in warranty.

Does anyone have any ideas why I would be getting a cylinder misfire error even though it is not misfiring?

Thanks for your help in advance.

Terry

 

[domesticpower]

Which sensor is it, do you know? I had a misfire problem and they said there's a TSB for a bad EGT sensor seal. The seal cracks and leaks, causing misreadings and resulting in misfires. Ford upgraded the seal and it should take care of the problem.

 

[VoodooBoss]

I talked to Terry about this a few weeks ago and I don't have a clue what's causing the misfire error. The clutch has been in the car for three years so clearly that's not the issue. The stock clutch is not up to track use so be careful installing a stock unit.

 

[TMSBOSS]

If the sensor affected is the crank sensor, then the metallic clutch facing of the RXT clutch may be affecting the sensor.

I believe the RXT has metallic facings and could be coating the sensor as they wear.

This could explain the need to remove the present clutch.

Have you pulled the crank sensor? Is there residue from the clutch on the sensor? Can this be cleaned off?

 

[cloud9]

What is the specific misfire code? If it's P0300 it's most likely related to the crankshaft position sensor. I had two fail during my ownership. As it relates to the clutch, Sean from AED posted an interesting thread on SVT a couple years ago. Apparently the CPS is magnetized and the metal shavings from aftermarket clutches can build up on it over time requiring removal and cleaning of the sensor.

If it's a P030x (x= 1 through 8.) it may be an engine wiring harness issue. There are some stickied threads on the options for upgrading it.

 

[TerryBoss302]

It was the crank sensor they just replaced.

 

[cloud9]

It was the crank sensor they just replaced.

Based on the age, that's not uncommon for it to fail on this car. You're fortunate you're able to run the stock engine wiring harness. If you had the upgraded one that was more often needed on the very early cars like mine, you'd have to send it off to Precision Race Services for the connector to be upgraded adding a week and $200 to the process.

 

[TerryBoss302]

The crank sensor did not fix it.

What I am hearing is to try the engine wiring harness?

 

[cloud9]

The crank sensor did not fix it.

What I am hearing is to try the engine wiring harness?

Can you get the specific DTC they pulled from the ECU?

 

[VoodooBoss]

He has the upgraded 2013 connectors from when the engine was replaced under warranty.

 

[Tucson 302]

When they replaced the tranny did they do a neutral profile relearn? If not that could be what's causing the codes

 

[06mach1]

One piece driveshaft and and clutch disc with no dampener springs?

 

[ArizonaBOSS]

When they replaced the tranny did they do a neutral profile relearn? If not that could be what's causing the codes

That is part of the service procedure any time the clutch or transmission goes in/out of the car, so they SHOULD have done it, but I agree--best to check, as this will definitely wreak havoc.

 

[TerryBoss302]

I checked with them. They said when they did the transition replacement they did the neutral profile relearn and they did it again a few weeks ago during troubleshooting.

I appreciate all the suggestions.

 

[SDS]

There's a thread on the P030X codes (https://trackmustangsonline.com/index.php?topic=2598.0) that have the list of what others have tried chasing CEL issues.

My car started throwing random misfire codes last year and going into limp mode. Into the local Ford dealer. After performing the TSB's, swapping out the cam and crank positioners, checking every sensor, the harness, the injectors - the codes continued and the car would go into limp mode immediately after trowing the code. The dealer had the car 4 weeks and couldn't solve the problem. Ford Racing finally authorized the dealer pull the engine and send the heads out to see if there was a mechanical problem. Nothing was found to be out of spec on the top end so the engine was assembled and re-installed. Magically, the problem disappeared... no more codes or limp mode issues. The car has been good or over a year including a dozen track days. All work was picked up by Ford.

Steve

 

[TerryBoss302]

I picked up my car on Friday and drove it home, ~10 miles. Did a few more miles on Saturday and no error code.

Ford says it is not misfiring and it just a sensor and not to worry about. I have a track day in a month so I will find out for sure.

 

[VoodooBoss]

I picked up my car on Friday and drove it home, ~10 miles. Did a few more miles on Saturday and no error code.

Ford says it is not misfiring and it just a sensor and not to worry about. I have a track day in a month so I will find out for sure.

Did they do anything else to your car? Make sure you have all of this in writing since your warranty expired. Good luck!