[skyking650]

Hi all,

Thanks for having this forum. I am a recent buyer of a 2012 Mclaren MP4-12C. It is a wonderful car.

I have in the last few days noticed an issue presenting itself and wanted to see if anyone else has or is experiencing the same before I take it down for service. A bit about the car.....

2550 Miles since new
Has the standard upgrades by Mclaren to up the power and other features

Specifically, during cold starts it skips and missfires which causes the Check Engine Light (CEL) to blink. This goes on for about 1 minute then the light goes off. Then last night after this cold start issue the car ran ok but after it warmed up, while driving and making a few hard acceleration runs (up to the posted speed limit of course...lol) i noticed it seemed to have a high speed miss.

Having been around race cars most of my adult life, the symptoms seem to be that of a spark plug or plug wire or coil issue.

I welcome any thoughts or suggestions.

Thanks in advance for your thoughts....

Tom

 

[roundincircles]

All I can advise is this is a new issue. Is your fuel good quality and what ambient temperatures do you have locally?

My car starts on command and burbles away even when left in the garage for a few weeks.


Sounds like an ignition or starvation problem, have you checked the points?

 

[6th element]

Agreed. Have witnessed the odd burb or fart on cold start-up, especially if the car has been sitting for more than a week. But she always settles to a smooth idle. Never ever had anything resembling a miss at speed. Get her looked at.

 

[jkheit]

Agreed. I'd have it looked at

 

[Walt of Destiny]

Mine with the cold weather does have a stumbly start up. But settles after 30 or so seconds. I would wait for the oil and temps to come up to spec before any high speed anything. But get her checked. If it's cold where you live you will have a little roughness. Sorry.

 

[andy c]

What everyone says,but there has been similar issues with poor fuel.

 

[Ritesh]

Having been around race cars most of my adult life, the symptoms seem to be that of a spark plug or plug wire or coil issue.

That would be my guess too. You need to call the service dept. and have them pick it up.

 

[CA_MP4]

It could be the purge valve for the charcoal canister of the EVAP system - I had similar symptoms and the valve was not cycling properly, was replaced and so far all seems fine.

Something the dealer has to diagnose, usually with uplink to Woking to have a factory engineer stick his nose into your computer........

 

[skyking650]

Thanks for all the quick feedback...and to clarify I didn't run it hard until after it warmed up. Having constantly changing weather here lately....from 70's to high 20's. Drove it today and did not have either issue. Have not changed or added gasoline since last night. Weather is about 55 degrees. Will take it next week to get looked at. In neutral it has always idled with a vibration...never real smooth. I dont know if that is common as this one has idled rough or with a vibration feel since the first time i started it.

Thanks again,

 

[AMLVantageV12]

It could be the purge valve for the charcoal canister of the EVAP system - I had similar symptoms and the valve was not cycling properly, was replaced and so far all seems fine.

Something the dealer has to diagnose, usually with uplink to Woking to have a factory engineer stick his nose into your computer........

I had the exact same thought.

 

[zippycar]

Sounds like an ignition or starvation problem, have you checked the points?

....

 

[snowhorn]

I had the same issue which was a multiple cylinder misfire code. Some smarter people than me noted that there is a batch of sensors in between the pistons that might be too sensitive. It has gone away now with code upgrades and flashing the system once that was installed...so I am guessing they were able to reduce sensor sensitivity. That being said my issues where during cold starts like yours but also very hot Texas summers. Hoping this summer it does not come back ...will keep you posted.

 

[Belg]

Did this eventually start after one of the updates? When was the last update?

 

[snowhorn]

for me it started in June '13. lasted the hot summer and then has not reappeared...10k miles on the car so it could just be a gremlin that faded away