closing off EGR valve

Does your Mitsubishi L300 make a strange noise? Need wheel alignment specs?
User avatar
BCDelica
Posts: 1808
Joined: Tue Jul 18, 2006 4:12 pm
Member's Photo Album: http://www.delica.ca/Photos/index.php?cat=10008
Vehicle: WVO Powered Tuk Tuk
Location: Central Van Isle
Location: Somewhere with plenty of sun

Re: closing off EGR valve

Post by BCDelica »

Just had to check the turbo on hers, seals are getting bad and the injection side of the turbo has a nice coating of oil. Here are pictures of a blanking plate with 80,000 to 100,000km's on it. The exhaust side has one small pit and the intake side (first pic) had coat of oil only.

Thanks for the motivation Mark.
Attachments
100_2075.JPG
100_2075.JPG (683.53 KiB) Viewed 4376 times
100_2074.JPG
100_2074.JPG (707.94 KiB) Viewed 4396 times
Image Call me BCDelica-less
User avatar
DelicaMark
Posts: 330
Joined: Mon Aug 20, 2007 9:37 am
Member's Photo Album: http://www.delica.ca/Photos/
Vehicle: L400
Location: Duncan, BC

Re: closing off EGR valve

Post by DelicaMark »

I was thinking about this thread the other day and thought I would close it up on my end with some hopefully logical thoughts. Here goes....

Understanding how the EGR (Exhaust Gas Recirculation) valve works and when it operates a bit better now has really got me thinking that disabling it really shouldn't do much for a reduction in smoke especailly when the van is under any kind of load. UNLESS the EGR valve is stuck open and is allowing exhaust gases to be recirculated through the engine all of the time, and as I understand it this may cause a less complete fuel burn resulting in an increase of smoke. If is working properly then the valve should be closed most of the time that you are actually driving. It should only be open when idling and maybe under really low load conditions (not sure about the low load conditions part). Therefore having it disabled really shouldn't do much for the reduction of smoke.

It seems to make sense to me (and I am sure other people have said this too) that a clean properly working EGR valve is as good as disabling it. The valve is normally closed so if you take it out to inspect and clean it, the valve should be closed. If it is stuck open then that could be causing some smoke. If you can't unstuck it for some reason then disabling it by blanking it off will stop the exhaust gases from being recirculated and likely help. I really question the results people have had by blanking off the EGR valve if the valve was actually fully operational in the first place. It seems like a nearly impossible result to me.

The cause of most black smoke seems to be directly related to injection timing, dirty injectors and valve clearance. If there was only a cure :wink:.

I do believe that some people disable it inorder to never allow heated inert gases from being recircultated into the engine at anytime which should result in a cooler cleaner air mix in the cylinders even during idling.

Hopefully this line of thinking makes sense...it does to me and has been tested with excellent results.

-Mark
User avatar
BCDelica
Posts: 1808
Joined: Tue Jul 18, 2006 4:12 pm
Member's Photo Album: http://www.delica.ca/Photos/index.php?cat=10008
Vehicle: WVO Powered Tuk Tuk
Location: Central Van Isle
Location: Somewhere with plenty of sun

Re: closing off EGR valve

Post by BCDelica »

I do believe that some people disable it inorder to never allow heated inert gases from being recircultated into the engine at anytime which should result in a cooler cleaner air mix in the cylinders even during idling.
What he said..... 8-)
Image Call me BCDelica-less
Post Reply

Return to “L300 Technical”