The exhaust gas recirculation valve is a component commonly found on many road going vehicles it is a part of the vehicles exhaust gas recirculation egr system an emissions system that is designed to recirculate exhaust gases back into the vehicles intake in order to reduce cylinder temperatures and nox emissions.
egr valves can malfunction by becoming stuck open or closed due to carbon buildup when an egr valve malfunctions co 2 is reintroduced to the combustion chamber at the incorrect time or in incorrect amounts which does not decrease the combustion temperature sufficiently enough to prevent the increase of nox.
This tutorial addresses a very common problem ive seen on the 19871995 gm 43l 50l and 57l engines with throttle body fuel injection system a stuck open egr valve and when the egr valve gets stuck open itll cause a rough idle condition that may hard to diagnose.
Faulty egr valve symptoms while some egr valve issues may actually be due to their control systems wiring and pneumatics etc most come about because the valve itself gets stuck open or closed due to buildup of soot particulates carbon deposits and a sticky tarlike substance.
egr valves that are stuck open cause poor idling engine misfiring and stalling if the valve is stuck closed a nitrogen oxide builds up resulting in knocking and incorrect engine timing mechanics can look for other causes by using a vacuum gauge to check for sufficient vacuum supply.
Span classnews_dtmar 11 2012spannbsp018332lol if one of those idiots could point to the egr valve or cooler id mail you 5 bucks to view links or images in signatures your post count must be 10 or greater you currently have 0 posts.
Span classnews_dtapr 07 2012spannbsp018332im very sorry i misread if it was stuck open it would do what i first saidif it was stucked closed you would have a check engine light on and a egr code in the computer and it might lack some power when accelerating and maybe some light hesitation or light bucking.
Span classnews_dtaug 01 2018spannbsp018332hard to say from here but it could have been stuck shut because of carbon just as easily as it being stuck open that said it should not have triggered a misfire code a dirty tb on the other hand can though id be hard pressed to explain why.
A stuck andor ruined egr valve will certainly cause reduced flow but clogging anywhere along the egr route can cause the same reductionand there are plenty of points at which that can happen luckily in most cases all you need to do is clean these components to restore the system to its full capacity which will turn off the check.