Miss not throwing codes.

[the sandman]

I have a 07 GT that has a definite miss at Cruise speeds and below. No codes are showing up. What should I look for? Thanks

 

[Juice]

Why is the misfire monitoring disabled in the first place?

 

[JC SSP]

Is this a new issue? Could be bad gasoline?

Connect a scanner with datalog capabilities and drive it to record the event.

 

[StockishS197]

You would need to scan for misfires to identify it if you want to target the specific cylinder.

To trigger a CEL, it has to trigger enough misfires per 1000 revolutions so it may be under threshold.

If you cannot use a datalogging software, start with the basics - pull coils, plugs and look for any inconsistent cylinders and replace any worn parts.

 

[the sandman]

Brother Juice; I didnt know they could be turned off. Brother JC; yes its new but doubt its gas as its a intermittant miss. Like one cylinder. Brother Stockish; Can I data log with my SCT x4? Is there instructions? Planning on keeping car as long as I can drive. Plugs have less than 5k but coils are unknown age.

 

[JC SSP]

SCT X4 does have datalog capabilities but as I recently found out… mine needed updating and 5,000+ files prevented me from doing it over WiFi. Last time I used it was over 5 years ago when I uploaded the tune. SCT was no help and doesn’t have live assistance or even a phone number to call and speak with a representative.

 

[Juice]

Yes, it can be turned off. Some tuners do it for cams.
If you actually have a miss, pull sparkplugs. One (or more) will look different from the others if there is a miss.

 

[the sandman]

Thanks for all the help. I dont think monitors are turned off as it has thrown codes in past. If it is a coil it will get worse. I will see if I can check header temps for a cooler cylinder. Im learning but the computer side will always be a stumbling block. I do need to learn to data log. Any suggestions? I too am disappointed with SCT,s lack of customer service.

 

[whitmanink]

so i had a stumble i couldnt figure out,,
ended up being the cop.

no codes nothing,,
and my misfire detection was on.

spark plugs and cop, all known to fail or go bad without notice

 

[MrBhp]

A word of advice. If you have to replace a coil, use OEM.

 

[86GT351]

Is this a new issue? Could be bad gasoline?

Connect a scanner with datalog capabilities and drive it to record the event.

Actually a scanner with Mode 6 capabilities should show these events if it is truley a misfire. Is the car in question an Auto or Manual?

 

[the sandman]

Manual and its not a dead cylinder, its annoying to hear. Im replacing A arms and tierod ends. So might get to miss soon.