Gen 1 coyote missfire No CODES

[newstang]

I have a 2011 coyote in my 69 stang. The other day it seemed to backfire from time to time and then had a missfire. The reader says no codes. so its not showing an issue but it is there. It comes and goes. I tried to disconnect one connector at a time for the coil packs and injectors. i thought i found one that made no difference and changed out injector and coil and i still have the missfire. I dont know where else to check. any help is appreciated. I did record the datalog but have no idea what to do with it.

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[robvas]

Upload the log to datazap

 

[Craig Brown]

My car runs great, but I get a random misfire and then it is followed by specific cylinder misfire codes. It never misfires, just throws a code. Changed all coils and plugs. Replaced the CAI with a JLT - FMG 15 updated the tune and replaced the purge valve. None of this has changed the code issue. (AI) says it is air flow turbulence in the intake tube. Fuel trims all look good. Did a relearn and that didn't correct the issue. Checked all air intake points for leaks, nothing there. ???????????????

 

[newstang]

Upload the log to datazap

datalog says my file is too large, unfortunately its the only one i have, all the plugs are out.

 

[newstang]

I selected a short part and uploaded it, but I have no idea what im supposed to do with this

 

[robvas]

I selected a short part and uploaded it, but I have no idea what im supposed to do with this

Start by linking us to it

 

[newstang]

Start by linking us to it

https://www.dropbox.com/scl/fi/exil...ey=abigtsdgwjd8jkpns07i00spt&st=xbpynwup&dl=0

 

[newstang]

https://www.dropbox.com/scl/fi/exil...ey=abigtsdgwjd8jkpns07i00spt&st=xbpynwup&dl=0

https://www.dropbox.com/scl/fi/exil...ey=abigtsdgwjd8jkpns07i00spt&st=xbpynwup&dl=0

this is the snippet from the big file

 

[newstang]

Ok, hope someone knows what i can look for. i changed out all the plugs and #3 cylinder shows no change when i unplug the coil pack. I have a new coil and injector on that cylinder and also used a NOID to check the injector as well as the coil wires and they are good. I think i have a problem with that cylinder. any thoughts ??

 

[horsepower addiction]

Are you running imrc’s can you compression test and leak down test the cylinder have you moved the spark plug to another cylinder or replace it?

 

[newstang]

I think I have it figured out. It happened once before and I forgot all about it. It was the alternator, if it puts out a low or shit voltage, it will buck and missfire. Im picking it up today and will confirm.

 

[newstang]

Well, not the alternator.

 

[newstang]

Are you running imrc’s can you compression test and leak down test the cylinder have you moved the spark plug to another cylinder or replace it?

Problem is I cant do any testing because none of my adapters fit the coyote, apparently there is an adapter for that spark plug hole and no one knows where it can be found.

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