Black08gt

I just installed the tune yesterday and as I was driving around.... when i would stop the idle would fluctuate from 250 to 1000 rpms. is there a fix for this??
Also my gas milage went to ****. any ideas on what could be the cause?

ski

The idle fluctuation is normal. The ECM is adjusting to the new tune. It should go away after 10 miles(+/-) of driving.
But if it'sidling erratically after driving for more than 20 miles, and the gas mileage dropped off a cliff, thenmake the correct tune was installed for the CAI. If it's the right tune, then it may be defective.

Black08gt

ok thanks I will be patient for the next little bit. but I think i have already hit the 20 mile mark but will give it a little more time

harraid5711

what 87 tune did you install? the canned tune that came with the device?? or one from brenspeed, bama, vmp, etc.....

Black08gt

installed the 87 from brenspeed

howarmat

Th poster above is incorrect. Idling down to 250 is NOT a proper operating vehicle. It might take time to get used to the tune, but it will not fluctatute like that. I am shocked your car didnt die infact.

Reload the tune
What octane gas are you running in the car currently
Call Brenspeed on Monday

Black08gt

i am running 87 also when i reload the tune do you have any advise on the operator select type things like idle and timing advance i left everything as it was.

harraid5711

he might be have you running a bit rich. email brent and perhaps he can either safely lean out your tune, adjust the idle rpms, or both. he'll take good care of you. sometimes it takes a tweak or two to get it right. also, just to make sure. double check your cai for any leaks, make sure the vaccuum hose is attached securely, and most important, make sure your MAF sensor is CLEANand tightly secured in your cai.

check my thread below for the importance of MAF sensor cleaning, i too had some idle issues.
https://mustangforums.com/m_4862882/tm.htm

rshamekh

The CAI is probably loose where it connects to the throttle body.

kcmarti

I had the same problem when I first loaded my tunes (87 & 93 Octane canned and 87 OctaneBamaChips). It did not go away after a couple of days of driving (for me the is about 250 miles), so I contacted Doug at BamaChips. He said they see this often on cars with CAI's and oiled drop-in filters like I have. The fix, one can of throttle body cleaner to clean out your MAF and throtlle body. Mine is now idling rock soild at 750rpm.