 Raising my Idle, '75 L-Jetronic idle |
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| jeff dodge |
 Jul 16 2026, 07:19 PM
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#1
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Newbie  Group: Members Posts: 29 Joined: 5-September 24 From: middleton,WI Member No.: 28,332 Region Association: None  |
My idle is very low. maybe 500 RPM's. I would like to raise the RPM so less warm up is required to start driving without restarting everytime I come to a stop sign. Thank you, Jeff
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| windforfun |
Jul 16 2026, 07:30 PM
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#2
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Advanced Member Group: Members Posts: 2,106 Joined: 17-December 07 From: Blackhawk, CA Member No.: 8,476 Region Association: None 
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Tweak the big slot head screw on the side of the throttle body under the air filter.
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| porschetub |
Jul 16 2026, 10:07 PM
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#3
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914 Guru Group: Members Posts: 5,139 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
QUOTE(windforfun @ Jul 17 2026, 01:30 PM)  Tweak the big slot head screw on the side of the throttle body under the air filter. Funny to read this as most ask how to reduce idle speed idle speed (air leaks) ,do adjust the air screw but make sure the timing is spot on before so ,cheers |
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| wonkipop |
Jul 17 2026, 12:53 AM
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#4
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914 Guru Group: Members Posts: 5,609 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille
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QUOTE(jeff dodge @ Jul 16 2026, 07:19 PM) My idle is very low. maybe 500 RPM's. I would like to raise the RPM so less warm up is required to start driving without restarting everytime I come to a stop sign. Thank you, Jeff do you mean idle is low at 500 rpm during warm - up only? |
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| wonkipop |
Jul 17 2026, 12:57 AM
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#5
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914 Guru Group: Members Posts: 5,609 Joined: 6-May 20 From: north antarctica Member No.: 24,231 Region Association: NineFourteenerVille
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QUOTE(porschetub @ Jul 16 2026, 10:07 PM) QUOTE(windforfun @ Jul 17 2026, 01:30 PM) Tweak the big slot head screw on the side of the throttle body under the air filter. Funny to read this as most ask how to reduce idle speed idle speed (air leaks) ,do adjust the air screw but make sure the timing is spot on before so ,cheers air leaks will mean L jets don't idle at all, or barely. not the other way around you are thinking of D jets? i suspect the OP is referring to a weak idle at warm up? which won't be assisted by the idle air screw as the idle will be too high when properly at operating temp. you only tweak the idle air screw with the engine fully warm for L jet (and anything for that matter - with as you note all other factors correct, valves, point gap etc). he has not come back to my question above. but it sounds like the classic lazy AAV that most of the L jets suffered from. it does not open wide enough at cold start. basically the AAV gets lazy with age. these early L jets even when new did not high idle on cold start up. mine has a lazy AAV - i bear with it and let it warm up for a good 5 to 10 mins before driving. just the way it is unless i send the AAV to the blokes up in queensland who do rebuild these things and promise to get them back into spec. but as i say even new the AAV was known to be productive of a slower cold start idle, not the usual higher 1200+ the D jets and most modern cars induce. |
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