Misfires

[TN GT]

Anyone having misfire issues? I had a couple in mid-November with about 1,800 miles on the car but none since until today. They seemed to occur in 3rd gear between 3-5k rpm (winding backroads). The CEL did not stay on either time but a warning was sent to the FordPass app on my phone.

Took some back roads today with my new base Lund tune flash and it happened again two more times in 3rd between 3-5k rpm. I do not think it was at all related to the tune. Each time the CEL flashed but did not stay on. 20 miles later, coming off the interstate, again I think in 3rd gear the CEL flashed and this time stayed on. Misfires on cylinder 2 and 4.

I was on my way to pick up some Ignite Red to test the flex and race tunes. When I flashed the ECU it cleared the codes. Several WOT runs and no problems with the flex or race tunes and then out of the blue it flashed again once more time but did not stay on.

I will run out the 110 and flash back to stock and see if I can get the CEL to come on and stay on. If so I will see what the dealer thinks about it.

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[ugstang17]

Did you perform the requested datalogs on the base tune and return them to Lund for review? Most remote tuners (I have used two different ones now and Lund is no different) request an idle and a sweep log on the base tune, and then a WOT pull in 3rd or 4th gear after they have verified the initial standing datalogs for proper air metering etc. The flash device will usually clear the codes (the exception to this being that irritating relearn crank trigger code which resets as soon as you perform rarnk trigger relearn through the handheld programmer). Lund is a reputable tuner. But remote tuning procedures need to be followed up on if they have not to complete the tuning process for optimal vehicle performance.

 

[TN GT]

Yes, I did send the logs. Again I don't think this is at all related to the tune since it was occurring one thousand miles before the tune.

 

[ugstang17]

Yes I read your vague statement the first time. Again, false assumption in troubleshooting often only bites you in the fleshy area, hence the reason for the response. I troubleshoot for a living. Been doing it a long time. It never ceases to amaze me how people want a simple resolve to a complex system without providing any detail, but they can quickly tell you what it isn't.

Does a person go to the doctor (a good doctor) tell him, "I had this cough 2 or 3 times at work last week. I know it's not a cold because I drink lots of orange juice. What's causing it?" No. Nor would the doctor respond, "Your sick" and send you home. He would ask follow up questions and use a process of elimination aligning with the symptoms (regardless of what you told him), review history, ask about daily habits, what you have changed in your diet, etc., to make a more accurate diagnosis. Yet when a technical troubleshooter asks a followup question he/she more often than not gets attitude. I am never ceased to be amazed that people will give their doctor all the 411 in the world to help diagnose an issue, but then cop an attitude with someone trying to help them properly diagnose their technical issue using the same method of analysis and process of elimination.

But since this isn't a doctors visit and I am not being paid to tolerate the attitude, take it to the dealer and have them resolve the issue. Have a nice day.

 

[TN GT]

I’m not sure what you are talking about honestly about copping an attitude or why you are taking this post so personal. In response to your question/statement as to whether I followed the procedure as directed by the tuner, I did everything requested by the tuner and simply stated as much.

I am very familiar with complex systems as well. I have been architecting, implementing, and troubleshooting extremely complex information systems for 20+ years.

I am not ruling out anything, had what appears to be the same issue before the tune, and do not what to jump to any conclusion that might impact the livelihood of a reputable tuner before I have all the information needed to make an informed decision.

 

[Notagain]

You already have a similar thread from before the tune.

Why not update the previous thread?

2nd did you or have you ever checked the plugs and plug gap?

Gotta start with the simple free things here first!!

 

[Bluemustang]

Yeah, something is causing the misfires. And I doubt it will just go away on its own. If that were my car I would get it looked at.

 

[TN GT]

2nd did you or have you ever checked the plugs and plug gap?

I will be checking the plugs in the morning if the rain ever stops.

Lund came back and said that the logs all looked good and recommended checking the plugs as well and setting them to .40.

 

[Notagain]

Its not just the gap. I suggest you look up how to properly read a spark plug. You need to check for cracked porcelain too, and the electrode strap, and where the threads meet the body...

 

[Blown86GT]

Its not just the gap. I suggest you look up how to properly read a spark plug. You need to check for cracked porcelain too, and the electrode strap, and where the threads meet the body...

Do you?

 

[Shifting_Gears]

I will just point out that the intake manifold runner control are known to fail and cause misfires. Yours sounds a little difffernt than the typical instance with those, but it’s at least something to chew on.

I believe that’s what’s happening with my GT and it’s definitely a lower RPM issue and I have gotten a P0308 code misfire on cylinder 8 twice. It goes away after a bit.

 

[TN GT]

I pulled the plugs and checked them today. They were all gapped at .53 and look okay. I changed the gap to .40. The car ran strong and there were no misfires. I didn't get to drive for long. I ran it on Speedway E85. The nGauge did a relearn and settled on 84.7% ethanol.

I broke the electrical connector on the fuel injector pump in the process of removing one of the coils and have it zip tied for now. I am not 100% sure that it had to be removed but the Ford Service Manual stated as much. If anyone has a guide for replacing the pins on that connector it would be much appreciated.

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