Mazzabl

well ive had my 2010 mustang gt for about 2 months now. i recently installed a steeda cai/AM custom tune, as well as a roush catback. the car has about 1300 miles on it. first question is, was it wrong of me to begin modding the car with such low mileage? also, ever since the intake/tune ive been experiencing very rough idle during cold start. its actually pretty violent almost as if the car has a huge cam in it, the car rocks back and forth a bit, it does this for about 5-10 seconds and then idles fine. im assuming this has something to do with the tune, but havent heard of anyone having issues like this with such a basic off the shelf tune. any input would be greatly appreciated.

Nuke

Define "huge cam" and give us a make/type. Cams tend to cause rough idle at ALL times, not just startup. And no, you didn't begin modding too early.

Contact AM and discuss your issue with them. They may rewrite your tunes.

You gave no details about your low mileage such as what it was and what it now is. Obviously, installing a CAI & tune will typically cause most drivers to get on it more often to experience and enjoy the additional power. Even at best, a CAI & tune won't normally provide fuel mileage gains unless you get a purpose-defeating economy tune (in which case you should have put the $$ towards fuel instead of a CAI & tune).

Mazzabl

give you a make/type of what? the car doesnt have a cam i was using that as an example of how rough the car idles.... mileage at the time i installed the intake/tune was just over 1200, it is now just over 1300, it was a week ago. i didnt mention anything about fuel consumption so im not sure why that was mentioned. im running the 93 octane performance tune. and yes, i am running 93 octane at all times.

Nuke

My bad.

Your thread title says "low mileage" and that was my 1st dud. The 2nd was misreading where you said "as if the car has a huge cam..." Guess I need more coffee...

Still, I'd contact Doug at AM and discuss your issue. If you had more mileage on the car, I'd suggest cleaning the TB and MAF but at 1300 miles that shouldn't be an issue. One other thought is to check all of the intake's clamps. You could have some air in-leakage that's throwing things off but not enough to throw a code.

overlord

Hey Nuke,

How does it run after the 5-10 seconds in the beginning, as in, coming to a stop and idling? I had a similiar problem when I had an air intake leak cause my buddy didnt put the cover back on correctly and would idle odd at times. It was trying to adjust and not getting a good reading, no code was thrown.

ski

If the CAI connections are tight, then reinstall the stock air intake and stock tune. If the problem goes away, then the AM tune is probably the cause.

Mazzabl

the car idles fine after about 5-10 seconds, its just that initial cold start where it idles rough. also it does not do this every day, its very inconsistant. is there a learning curve for the ecu to learn the new tune? if it continues ill give AM a call.

ski

The ECU normally has to relearn the idle whenever a new tune is installed, or the battery is disconnected. But I've never heard about the idle becoming rough after doing either.
FWIW, there's a procedure in the battery maintenance section of the owner's manual for helping the ECU to relearn the idle that may solve your problem.

Mazzabl

thanks, ill have to look into that. your running the race tune for daily driving? i was debating between running the performance tune or race and wasnt sure if the race tune would run too lean for daily driving and worsen reliability. is the difference noticable between between the two?