gb20 Posted May 5, 2009 Share Posted May 5, 2009 Hey guys, I just got the 4 barrell intake from arizonazcar.com put on my 260z. I really like the look of it and it fires right up now (it would take a minute or so in the mornings to fire with the old 2 carb set up). The problem I am having is that it is idling at 4,000rpms. That's 1,000rpms past where I normally shift. I have tried to adjust the idle screws on the carb with no affect. Do you guys have any suggestions on what to do to get the rpms back down to around 1,000rpms at idle? Thank you for any help you can give. gb20 Quote Link to comment Share on other sites More sharing options...
gjc5500 Posted May 5, 2009 Share Posted May 5, 2009 Check the linkage, make sure its not bound. also check the idle set screw. Quote Link to comment Share on other sites More sharing options...
slown280z Posted May 5, 2009 Share Posted May 5, 2009 Make sure you aren't bypassing the throttle somehow. Quote Link to comment Share on other sites More sharing options...
jt1 Posted May 5, 2009 Share Posted May 5, 2009 Yeah, it sounds like a vacuum leak. jt Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted May 6, 2009 Share Posted May 6, 2009 No mere vacuum leak would cause an idle that high. I vote binding somewhere. Disconnect the linkage from the carb. Check to see that the primary throttle plates are almost fully closed. Check to see that the throttle plates move smoothly when operating the throttle mechanism. If all these check ok, note the position of the arm actuating the throttle on the carb, then attach your linkage and see if that arm has moved - you can verify by checking the throttle plates in the primaries too. Quote Link to comment Share on other sites More sharing options...
GOTAZ Posted May 6, 2009 Share Posted May 6, 2009 I'd second Brad-ManQ45's ideas. I have a 0.5 inch gasket between a 4bbl and a similar intake. I installed it to actually help insulate the carb from heat but it also provides more clearance for carb linkage. Too, be certain the electric / manual choke is adjusted and operating correctly. Make sure the throttle return spring(s) are providing enough tension and aren't getting hung up or going over-center. And, check the carpet and floormat in the driver's side footwell. Tho not likely related to changing intake & carb setup, a loose floormat that has slid (slud?) forward and jammed the loud pedal can happen. Been there, survived that. Good luck. Quote Link to comment Share on other sites More sharing options...
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