1993 mustang gt idle up and down, just happened

Hi
I just noticed my idle fluctuating on my 93 mustang gt.It seem to go between 500 and 900 rpms It only seemed to happen after installing my bbk mass air flow sensor or my underdrive pulleys. I just put both these items on within the last week. before that the car was stock an dI did not notice any idle problems. I also added the bbk cold air intake, but I did that first about two weeks ago and it idled fine after that.

Is it possible that my alternator is bad or to weak and I just noticed it with the underdrive pulleys? If so should i go with the 95 or 130 amp alternator? ( I do not have any aftermarket stereo equipment)

I read the forum on the idle issue,but it was fine before i added the two items listed above.

Any info is appreciated

Thank you
 
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My first thought would be to look hard at any vacuum line you may have inadvertently disconnected or broken during your most recent install.

After the install(s), was there a time where it ran correctly at all?
 
See the "Surging Idle Checklist for help with all your idle/stall problems.

The quick and easy way to dump the codes is in there too, and all you need to do it is a paper clip! The first two posts contain all the fixes & updates. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.
 
more than likely its the bbk maf sensor. is it calibrated for 19lb injectors? if so, go ahead and reinstall the stocker and see if that cures the issue.

I will try that today, yes I bought the bbk maf sensor for 19 lb and it is cold air calibrated. If the stocker cures the issue should i leave it or do you guys have any other sugestions on a better afternarket maf?

Also , do i have to reset the computer after I change it and how do I do that?

Thanks again!
 
I will try that today, yes I bought the bbk maf sensor for 19 lb and it is cold air calibrated. If the stocker cures the issue should i leave it or do you guys have any other sugestions on a better afternarket maf?

Also , do i have to reset the computer after I change it and how do I do that?

Thanks again!

resetting the computer is a simple as disconnecting the battery for a ~20-30 minutes.
what size is the bbk maf unit? you could go with a 75mm pro-m or pmas meter calibrated for your injectors. i would steer clear of the c&l as they are hit or miss.