2011 Mustang GT a/t cold start - hiccup - surge

[joe zei]

hey guys, im new to the group and wanted to pick some of your well informed minds,

i have a 2011 mustang gt, all maintenance always done on time. stock other than mufflers. on a cold start (intermittently) im getting a hiccup, and then a "clunk" sound. spark plugs are NGK iridium and done not that long ago , synthetic oil changes every 4,000km, and premium gas only at shell, its driven very little (2,000km a year) and stored in the winter. not sure what to do, i booked diag time at my local ford dealer but im not always able to replicate it. once it warms up it idles fine. no codes


current odometer reading 91,500km

heres a vid of what happens

ff to 20 seconds in

 

[Sky Render]

Get rid of the shitty aftermarket plugs and put factory Motorcraft back in.

 

[joe zei]

This was happening before i ever considered spark plugs to begin with

 

[Sky Render]

Hmm, I listened to the video, and that is definitely not normal. No pending codes? Can you view the AFR? Does that miss happen when the ECU is in open loop (AFR will read 0.00)? The ECU is in open loop for a very short period of time immediately after cold start.

If it's occuring during closed loop, I would suspect a bad heater circuit on one of the wideband O2. (Perhaps it is not getting up to temperature quickly enough.)

Are the coil packs still original?

 

[john knox]

hey guys, im new to the group and wanted to pick some of your well informed minds,

i have a 2011 mustang gt, all maintenance always done on time. stock other than mufflers. on a cold start (intermittently) im getting a hiccup, and then a "clunk" sound. spark plugs are NGK iridium and done not that long ago , synthetic oil changes every 4,000km, and premium gas only at shell, its driven very little (2,000km a year) and stored in the winter. not sure what to do, i booked diag time at my local ford dealer but im not always able to replicate it. once it warms up it idles fine. no codes


current odometer reading 91,500km

heres a vid of what happens

ff to 20 seconds in

i have 06 that would do that run fine then out no ware run like shit then clear up some time not at all for 3 days, it was tbs, it was a ford deal for 2 weeks, i dont have a scope, 3 month later the tbs finely shit the bed new fomoco tbs, no more ruff idle

 

[joe zei]

Hmm, I listened to the video, and that is definitely not normal. No pending codes? Can you view the AFR? Does that miss happen when the ECU is in open loop (AFR will read 0.00)? The ECU is in open loop for a very short period of time immediately after cold start.

If it's occuring during closed loop, I would suspect a bad heater circuit on one of the wideband O2. (Perhaps it is not getting up to temperature quickly enough.)

Are the coil packs still original?

original coil packs, no pending codes, not sure what an afr is, but what would you steps should i take now?

 

[Sky Render]

original coil packs, no pending codes, not sure what an afr is, but what would you steps should i take now?

Air Fuel Ratio. Can you read the two wideband air fuel ratio as seen by the ECU using a scan tool or OBD reader?

 

[joe zei]

I have an obd, I’ll check the next time I start it.

 

[joe zei]

Anything else I should also look into before Diag at the dealer ?