Originally Posted by Vaughan1023
Hey guys, I'm new to this page. I could use some help diagnosing my problem with hanging rpms. My 2004 GT had rarely done this so I never paid attention to it. Recently I just installed a BBK 78mm TB/Plenum and my rpms are hanging really bad. I will take it out of gear coming to a stop sign or red light and my rpms stick at 1500rpm and slowly drop down to normal idle when I'm at a complete stop. My car is also Bama tuned but I do not believe the tune is causing this. What could it be?
Hey Vaughan1023 - Welcome to MustnagEvolution. Sorry to hear that you're running into trouble. I'd have to side with the rest of the fellas in here and I would start right with the throttle intake.
If this were a cold air I would start by hunting for a loose line but what's happening isn't in direct relation to the problem at hand and you're going to need to take a look at your tps.
This is a super, super common issue and the link for the post below should get you set up.
If you're having any trouble with this shoot my customer service team a call and they're happy to get you some help.
Let us know how you make out.
Originally Posted by Kris.R
Go to post #9
Throttle body screw - Ford Mustang Forum
Your vacuum lines have nothing to do it with it. BBK is known to not machine the bore of the TB where the plate is housed properly. Just search on google and you'll find TONS of threads from different forums about your issue.
The whole "factory setting" for the throttle plate isn't something to be religious about as there can always be a simple error in assembly that could cause your issue. It never hurts to check.
As far as adjustment goes, when you look at the top of your TB you'll see the screw. Get a feeler gauge in there and check for proper clearance