Sandy455 Posted February 17, 2016 Share Posted February 17, 2016 Running my L24 with SU's in a '70 240Z for track and street. After driving the car for more than 30 minutes, the idle begins to decrease. Like if I start the drive with the idle set high, around 1100 rpm, after driving it or multiple run sessions on the track, the idle will lower towards 900 then lower. Then if I'm caught in stop 'n go traffic, the idle sometimes suddenly just drops out and the car will die. Thoughts? Thanks. Quote Link to comment Share on other sites More sharing options...
Miles Posted February 17, 2016 Share Posted February 17, 2016 (edited) Go here and buy the "Just SUs" video: http://www.ztherapy.com/ Edited February 17, 2016 by Miles Quote Link to comment Share on other sites More sharing options...
Sandy455 Posted February 17, 2016 Author Share Posted February 17, 2016 Go here and buy the "Just SUs" video: http://www.ztherapy.com/ Thanks. I have that DVD. I bought my SU's from ZTherapy. Doesn't really address my issue though. Quote Link to comment Share on other sites More sharing options...
Miles Posted February 17, 2016 Share Posted February 17, 2016 (edited) When the idle speed starts falling, what happens if you put the choke on? Edited February 17, 2016 by Miles Quote Link to comment Share on other sites More sharing options...
Sandy455 Posted February 18, 2016 Author Share Posted February 18, 2016 (edited) When the idle speed starts falling, what happens if you put the choke on? I don't have the choke lever installed anymore. Edited February 18, 2016 by Sandy455 Quote Link to comment Share on other sites More sharing options...
Miles Posted February 18, 2016 Share Posted February 18, 2016 Check for vacuum leaks. Check floats. Check linkages http://www.britishcarforum.com/bcf/showthread.php?86104-Su-Carbs-Won-t-Idle Quote Link to comment Share on other sites More sharing options...
Sandy455 Posted February 22, 2016 Author Share Posted February 22, 2016 Thanks. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 22, 2016 Share Posted February 22, 2016 Check fuel pressure. Make sure its constant at 4 to 5 psi. Low voltage to the pump at idle could cause a drop in pressure. Quote Link to comment Share on other sites More sharing options...
bradyzq Posted February 23, 2016 Share Posted February 23, 2016 Heat soak? Vapour lock? Quote Link to comment Share on other sites More sharing options...
Samurai7one Posted May 6, 2016 Share Posted May 6, 2016 My car does the same thing when I get stuck in traffic. I can watch the temp rise, AFR go lean and RPM drop. Normally i idle at 1000 rpms but on a hot day stuck in traffic my rpms will drop to 600. Once I break out of traffic and row through the gears then everything goes back to normal. Try adding a heat shield and header wrap if applicable. or re think your fan/radiator setup. Quote Link to comment Share on other sites More sharing options...
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