[Nemo777]

I have a 2016 mustang ecoboost. I put in a new engine and have 400miles on it now. I have put in new spark plugs and have done a crank relearn. My car still misfires at idle and start ups with NO CODES. Please help

 

[Joshua Iiams]

I have a 2016 mustang ecoboost. I put in a new engine and have 400miles on it now. I have put in new spark plugs and have done a crank relearn. My car still misfires at idle and start ups with NO CODES. Please help

How can you tell that it's missing. Is it idling rough? Do you see the engine shaking more then usual? Do you have some gauges up that indicate misfire counts on idle? If it misfires enough you should see some trouble codes that indicate which cyl is missing.

 

[Nemo777]

How can you tell that it's missing. Is it idling rough? Do you see the engine shaking more then usual? Do you have some gauges up that indicate misfire counts on idle? If it misfires enough you should see some trouble codes that indicate which cyl is missing.

My cob shows me the miss count.

 

[Joshua Iiams]

My cob shows me the miss count.

If it's a low count I wouldn't worry too much. These engines misfire from the factory and as long as the misfire counts are below a certain threshold it's nothing that will destroy the engine. I'd keep tabs on your ign corrections and see if you are getting consistent neg corrections or pos corrections.

 

[Nemo777]

If it's a low count I wouldn't worry too much. These engines misfire from the factory and as long as the misfire counts are below a certain threshold it's nothing that will destroy the engine. I'd keep tabs on your ign corrections and see if you are getting consistent neg corrections or pos corrections.

 

[Joshua Iiams]

View attachment 41322

 

[Nemo777]

Is that bad

 

[Joshua Iiams]

Is that bad

I am seeing some negative corrections on cyl 1 and 4 which is never good. A log would help identify if it's doing that for extended periods of time. Are you tuned? Maybe reach out to your tuner.

 

[Brian2121]

I have a 2016 mustang ecoboost. I put in a new engine and have 400miles on it now. I have put in new spark plugs and have done a crank relearn. My car still misfires at idle and start ups with NO CODES. Please help

Have you found the issue? I’m having the same issue. The dealership near me is charging me $200, but there is no code. Spark plugs look clean and car runs fine at high rpm’s.