egr sylinoid

what does the egr sylinoid do? is it necissary? I fallowed the instructions from this tech article on fixing blow by http://www.jeepxj.com/JeepXJ/oil blowby fix.htm
and when I was about half way done i realized that my egr sylinior was getting disconected. It runs fine, but they wouldn't make a part with no perpose.

thanks,

ben

The EGR valve is normally closed. When the computer needs to open the valve it sends a signal to the EGR vacuum solenoid. It allows vacuum to the EGR valve thus opening the valve. Allowing a small amount of exhaust gas to enter the intake manifold lowering the combustion chamber temp. This has to work as its main purpose is to reduce NOx emissions. If your not worried about passing a emissions test leave it disabled. BUT YOU WON'T PASS AN EMISSIONS TEST WITHOUT IT CONNECTED AND WORKING PROPERLY!!!!

aNDY

As I recall, the egr solenoid also controls the evaporative canister purge, so it's best left connected, and if you have egr problems, just block the vacuum line to the egr valve itself until it's fixed. I believe also (can't guarantee from memory) that the solenoid itself defaults to "open" for the egr valve, so if you leave the vacuum line connected but pull the electrical plug, it will not work right.

won't that guaranteed to pass stuff work for emissions? will it run fine though??

bigpimpinben said:

won't that guaranteed to pass stuff work for emissions? will it run fine though??

Click to expand...

Not quite sure what you mean here, but if you leave the solenoid connected, and block or crimp off the line to the egr, the engine will run just fine. If your egr valve is sticking or leaking it's a good temporary way to keep running. I'm not sure just what happens if you disconnect the solenoid itself, but you might end up with a little vacuum leak if it defaults to "open" and your gas tank vent system might not work right. In theory, the egr should help reduce knocking, but the knock sensor handles this anyway, so disconnecting the egr valve itself will not give you any noticeable change in performance, but if it works you should leave it connected. The knock sensor operates by retarding timing, so anything, such as a working egr, that reduces the need to do this should be beneficial to performance and economy, if only slightly. The XJ emissions system is well designed, and disabling it will not improve performance.

Mine has had the vaccume line disconnected for about a year and a half now with no effects that I know of. But I also don't have to pass emissions.
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