Page 1 of 1

principles of EGR ? explain please ?

Posted: Tue Aug 21, 2007 10:05 am
by steptoe
anyone know the principle behind the workings of EGR system, esp in EA82T?

wanna know when the EGR valve is meant to activate to allow the recirculation, like at

* idle only,
* light throttle only or
* flat out or
* all of the above

there is on all EA82's a vacuum switch that also has 2 wires, on the driver side of the inlet manifold that provies control to the EGR valve on the passenger side of inlet manifold.

My GLTA is coming up code 3-5 , short or open circuit of egr solenoid which may explain the intermittent miss on #2 seems to be vacuum leak origin - suspecting something is sticking open like the vacuum switch (might be dirty inside)

ta

oh yeah, some consideration also for when there is boost pressure with turbo ?

Posted: Tue Aug 21, 2007 5:52 pm
by Gannon
My understanding is that it recirculates a bit of exhaust gas during cruising to lower combustion temps and reduce NOx emissions

But isnt the EGR solenoid on the passenger side of the motor, and thus only affecting cylinders 2 and 4?

Posted: Tue Aug 21, 2007 9:59 pm
by El_Freddo
Yeah the EGR is on the passenger side but somehow keeps the system in check - dunno if it has it's own channel that follows back to the throttle body, would have to have a look and can't be bothered at the moment (dark and cold outside)...

The idea is as suparoo has said... if you stick your finger in the gap to gently touch the diaphram and rev the engine using your other hand, you should feel the EGR diaphram open and close. If not, its dodgy and could be where the leak is from but still couldn't explain why it effects only number two cylinder.

Check out the EA82 manuals at the bottom of this thread, might be worth a read - a few pages to go through but using the contents page may make finding the info easier...

Hope that's of some help...

Cheers

Bennie

Posted: Wed Aug 22, 2007 2:10 pm
by discopotato03
I think you'll find that one solenoid is for the EGR valve and the other is a fuel tank vapor line purge valve . I can't remember which is which but one always breaks its plastic barb off .

A

Posted: Wed Aug 22, 2007 10:02 pm
by steptoe
thanks guys, yup , I must be lucky coz the solenoid off Damo666's auto carby EA82 is intact and WORKS. The others both razzed and /or broken barbs. Both EGRs work with mouth suc(yuck)tion. Watched vacuum gauge 'T'd inline and does not open EGR at idle. The EGR has its own port to the plenum chamber so you'd think it was common to all runners offf it. Having plated and sealed up the port under the EGR valve last night so no air can leak past EGR to inlet.....PROBLEM HAS GONE..no intermittent miss on #2 all afternoon


curious??