Andre3000 55 Report post Posted October 10, 2013 I'm having an issue sorting an idling problem with an m40b18. Its worse when cold and coming off revs into neutral (its a manual). Idle drops to 400 and jumps up to 1100 and continues to bounce between this if left to its own devices. If I feather the throttle a tad and let it gradually down it will bounce between 550 and 800. What I've done so far Checked for vacuum leaks - none Replaced leads & sparks - no difference Cleaned throttle body - no difference Checked fuel pressure - Ok I'm about to replace the dizzy cap and rotor as its pretty f**ked, hopefully this will make a difference. Is there anything else I should be considering? There is a blocked air hose to/from the right side of the carb and also a unused 2 pin plug hanging from the same wire as the AFM. Any idea what could be missing here? Also I've noticed that the fuel canister has been disconnected and does no longer exist... Quote Share this post Link to post Share on other sites
dubman 39 Report post Posted October 10, 2013 the disconnected screw end hose + plug is for emmissions canister? iirc the stalling might be a dirty throttle position sensor (oil plus other goop goes in from the bottom of the throttle butterfly pivot). also, check idle control valve, it should make a "click" sound when the key is turned from off to the 2nd ON position (before cranking), and another "click" when you pull the key out (idle valve opening/closing). plus give it a good clean Quote Share this post Link to post Share on other sites
