My spin on an old problem


15 Year Member
Sep 15, 2006
St. Louis, MO
I have just installed a trickfloy plenum and frpp 70mm tb on my 04 gt. I now have a strange type of rpm hanging that I have yet to see when searching old threads. My rpm likes to jump 100-250 rpm everytime I take my foot off the gas and press the clutch pedal. In addition my enginge rpms drop but freeze for about 3-7 seconds at 2100-2200 rpm and then again at 1600-1700 rpm. Could it be a selectively sticky IAC? Does anyone think that the computer is still learning? Its been 2 days and around 150 miles since I last disconnected the battery for 25 minutes. I have been known to fix things until broken so I wanted everyones opinion on whether to pursue repairs or remain patient. When the engine finally does fall to idle, its pretty normal around 800-850 rpms. I checked for vacuum leaks with carb cleaner and no sign or sound of one. The tb does have the small hole in the blade. I dont have a cai. The tps is properly adjusted to .98v at idle. Where do I go from here?
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Give it a week. Mine took that long, but it only got about 90% better. With the freeier breathing, it just won't fall as it did. Later, I also help the situation with the copper pipe mod, which essentially restricts air going into the air box - take the hose and go to the plumbing section of your hardware store...check for the best fitting copper plug, then drill a hole in the (3/8" I think is what I did - better to start small than too big!) center and re-assemble.