<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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--></style></head><body lang=EN-US link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt'>It has been about 25k miles since I restored Elwood, and I have always had to restrict the IAD inlet to get it to idle down to 850rpm to set the timing. ( yup: ’72 with dual diaphragm vacuum canister w/ ports plugged). After every tune-up spec is set: the resulting idle speed seems to be a little higher than the previous last year - to where I can’t bring it down to spec, so I live with it. As of today the idle is around 1300 and I’ve had enough, so I’m trying to get to the bottom of it. All my FI components are the correct ’72 versions.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'>The idle screw is just an air bleeder screw, but it is ALL the way down to be shutoff. Vacuum canister is new, and it properly does the job of bringing the idle down about 80rpm at idle when plugged in. Fuel pressure @ 30. Plugging the warm aux air regulator results in only a minor drop of about 30rpm, so that’s working. I have sprayed SO much carb cleaner around any & all intake gaskets & seals & injector areas that I must have the cleanest engine out there, but zero change in rpm to find any air leaks. I even made a bent carb cleaner nozzle hose to spray on the underside and backside of the IAD. Cold start valve has never been hooked up, but no rpm change when sprayed with carb cleaner. Rubber air intake tubes test good for no air leaks as well. I have the ’72 decel valve installed & working, but plugging it for a test showed no issues. Readjusting the throttle switch made no idle difference. I substituted a known good spare pressure sensor, but made no difference at idle.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'>If it’s a warm engine – and then I shut it off for say 30 minutes – it will start right up and idle correctly for about 20 or 30 seconds, and then it will increase itself back up to 1300 within 1 minute or so.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'>When warm – I can put my finger inside the throat of the IAD and totally plug the inlet “port” for the idle speed screw. This 100% plugging will result in a 850 or so idle speed (with the idle speed screw still all the way in and throttle plate still closed).<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'>IIRC – the 2 FI heat sensors have very little to do with idle speed, but please correct me if I’m wrong about that.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'>I do have a backup brain I could substitute, but I’d like to hear any feedback before I go that route.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'>Sorry for the long post… I’m trying to give all info.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;mso-ligatures:none'>Dave Pallo<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;mso-ligatures:none'>’72 Square ~ Elwood<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;mso-ligatures:none'>Fairport, New York<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'><o:p> </o:p></span></p></div></body></html>