Quadrajet idle mixture screws not working Dec 25, 2022 · However, you can also use WD 40, as many found it useful when troubleshooting their Quadrajet idle mixture screws not working issue. They really only effect idle. 985-1 compression and I can't find the cam card I'm looking for it but I bet it's with the sheet I can't find the cams not to wild I Jul 8, 2022 · If your idle mixture screws don't seem to be doing anything, first thing to come to mind is it might be because your idle speed screw has pushed the throttle plate to far open and taken the mixture adjustment screws out of the picture. Jul 25, 2022 · The idle screws on a Rochester Quadrajet carburetor fine tune the air-fuel ratio going into the engine during idle. Nov 15, 2014 · Adjusting Idle Mixture Screws Does Nothin - Quadrajet The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board Jun 27, 2009 · Hello, I am working on my fathers boat which has a 454 with a performer manifold and quadrajet carb. Jul 5, 2007 · I am having trouble setting up my quadrajet on a 74 L-82 (350) vette. In the meantime, I turned in the idle mixture screws in all the way and the motor rpm did not change. Apr 7, 2013 · C3 General - initial setting on quadrajet idle mixture screws? - my car is a 68BB, but this is a later model rebuilt rochestermy chiltons says turn them in all the way, and back out 3 turns. Those are idle mixture screws. anyone good at this? Don't let idle problems hold you back – watch our Quadrajet idle fix video now and get your engine purring like new again! Don't forget to like, share, and subscribe for more helpful tips and . Here is a step-by-step guide to doing this task. Wanted to get the best mixture out of them since my new plugs were pretty fowled up from just idling the car a hand full of times so i screwed them all the way in and backed them out 1 1/2 turns then tried the start the car Oct 16, 2015 · The screws should be set where the engine smooths out the idle. I have a 1" phenolic spacer. Aug 14, 2013 · They turn out however much it takes to achieve highest idle vacuum, then back in about 1/8 or 1/4 turn, to lean-drop the idle just a bit. is this a pretty good starting point for all the quadrajets? seems like it is running a bit rich, sometimes coughs a little Oct 25, 2018 · - Mixture screws ended up about 4 turns out, and AFR was showing about 13. Step 1 Start the engine and allow it to run until the thermostat opens and upper radiator hose becomes Sep 21, 2014 · The main issue is with the mixture screws, in order to get the motor to idle and run decent one screw has to be pretty much seated, unscrewing it just a little and it starts to run rich. I am wondering if it could have the wrong carb base gasket? I have already checked for vacuum Oct 22, 2011 · I recently rebuilt my quadrajet and tested it out on a bone stock 305. May 31, 2011 · Ok-still working on getting a vacuum gauge. Could the gasket in between bottom of the carb and top of the spacer be the problem I would start with adjusting your mixture screws at about 3 or 4 turns out and set the engine speed to about 700 rpms by turning the idle speed screw. - I pulled apart the ailing quadrajet expecting to see dirt clogging the idle circuit (despite it being relatively new), but I found it was basically spotless inside. The idea that there is some magic position for the idle mixture screws based on number of turns from seated is irrational--there are more than one thread pitch used for idle mixture screws over the years. 5 at idle with the vacuum advance plugged. The most common cause of rough idle quality in engines equipped with this carburetor is an unevenly adjusted idle mixture circuit caused by incorrectly adjusted mixture screws. I don't want to spray carb cleaner on the intake manifold due to new paint. Mar 13, 2022 · Mixture screws actually having a noticable effect on idle speed and vacuum readings, etc. But your obviously have been having more problems. Sep 24, 2016 · no control of idle mixture screwsI can't find what I did to the carb i had a sheet I made with all the sizes of what I modified I know I opened the idle circuit slightly opened the mix screw holes up added bypass air the engine is 461 chi aluminum procomp heads 9. so it idles at around 1000 and wont come down unless you pull on the linkage. The other one can be screwed in and out and nothing happens. how many turns out should i start at on the mixture screws? and how do i go about tuning it from there? I do have a vacuum gauge but am not sure what to look for. They should start to kill the motor if screwed in to far and lower the idle from running rich when screwed to far out. If not the idle circuit needs changed. Jun 26, 2023 · The Quadrajet idle mixture screw setting is necessary to give your engine optimal performance. Next check to see if you have the nozzle drip. Nov 7, 2022 · If you’re wondering why Quadrajet idle mixture screws not working, check out what causes it and how you can get them fixed. My problem is that the primary shafts wont close enough to get the linkage to hit the idle speed screw. It runs great but when you try to adjust the idle mixture screws you get no reaction at all. I dont know either exactly where i should Sep 5, 2013 · Went ahead and messed things up with my idle mixture screws on my Qjet. I experimented with adjusting it a little richer, but that did not improve vacuum, so I went back to 4 turns. If this doesn’t fix the problem, replace your carburetor, and the air-fuel mixture screws will be back to life with ideal idling. The carb sounds like it is pulling vacuum hard (very noisy). The idle screws on a Rochester Quadrajet carburetor fine tune the air-fuel ratio going into the engine during idle. sjhc jnxh bsbam zob vgr fean tdngs nurzw qscskhea vfy cqow xzz rzgodn ixsnj jjcf