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egr valve


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haven't tried to clean one, since I don't have to emission mine.  first check with a vacuum pump to make sure its holding a vacuum before assuming its just clogged.

 

on mine I believe there was a snap ring or something on the inner valve part, no idea to what degree it comes apart

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the ecu can't actually suggest the EGR is at fault as it does not have any elcetrical connections, but I think code 34 is refering to the solenoid valve that controls the vacuum to operate the EGR. Stick to open, or stick to close I think are the words. The only ECU code I have had on mine when I got it and assembled things and was spot on, not some flippin' red herring like ECU codes can be!

 

The solenoids can be found on many EA82 and EA82T to replace it with. Can be a pain to get at some on turbos, but easy to test, just put 12v across ther terminals and listen for a click open, and shut. Maybe shorted internally use a fuse and see if it blows fuse.

Be a good time to check and clean your PCV valve at the back of the inlet manifold too - 19mm spanner.....

Edited by jono
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what should the EGR hose hook up to? Mine was missing...I put a line on it and tapped into a manifold port that I found was un-capped and the engine died...but a lot of the emmision stuff was gutted already so no telling where it was plumbed originally

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new PCV ? That's rare down under ! The little fibre filter pads would be a rare replacement also, the ones in the air filter box..

I did not have a blown fuse myself, just found solenoid did not work.

As for odie, my factory manual describes EGR function as to operate only at operating temp + below 45 kph? + the way the vacuum controls it between about 2 and 10 inches of mercury Hg. Killed the theory that you gain 10kW by blocking off the EGR, unless they measured extra 10kW at light throttle rather than max power revs - there is no vacuum to operate an EGR on an EA82T !

You hook up vacuum at idle and valve actually breathes - you will stall it, coz you are feeding exhaust into inlet manifold.

 

My ecu has not controlled EGR as it should, does it at all temps, all speeds above idle just with vacuum being at corrct levels to open diaphragm.

 

You could hook up a micro switch on accelerator function to close of solenoid vacuum at idle ?

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odie - the EGR valve itself is just bolted to the manifold.  all the EGR activities are internal, it has 1 vacuum supply line that just goes to manifold vacuum, and one large hose outlet that normally goes to the anti after fire valve and can be plugged if you don't have it anymore.

 

if you leave the vacuum supply line off it shuts off the EGR function.  you can do this if you plug the nipples, though i would only do it if the EGR is faulty.

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To be clear EGR should not be hooked to Manifold Vacuum.

 

It should be hooked to Ported vacuum, just above the throttle plate.  I believe with SPFI this is the port at the front base of TB, right side (left looking from front)

 

All the solenoid does is close off the system til warmed up.  Once it's warm....it opens to pass ported vac to the valve itself.  Ported Vac opens EGR when Above throttle vac is high.

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is the EGR port different on a carb car?  both of mine when they had all the stock configuration were going to manifold vacuum.  tbh now that I think about it that sounds right.  supposed to work at light throttle which would be largely the same whichever port you use, but full vacuum would open it at idle.

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is the EGR port different on a carb car?  both of mine when they had all the stock configuration were going to manifold vacuum.  tbh now that I think about it that sounds right.  supposed to work at light throttle which would be largely the same whichever port you use, but full vacuum would open it at idle.

 

Then they were hooked up wrong.

 

EGR is always operated by above throttle vac port.

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So I just cleaned up the egr and put on a new gasket (old one was trashed) felt the diaphragm while given it gas it "kinda worked" it would flinch but if I gave it some help it worked properly... any new ideas? BTW vacuum line seems to be good

Edited by drake13
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Did you read my posts ? (said in a soft, cool text) If you still need to clear the code, and if code 34 is for the EGR valve - you need to attend to the solenoid which should be on a black wire and blue wire in a white connector. Solenoid itself bolted to inlet manifold with an M6 , 10mm head bolt - this is what is yelling for help to the ECU.

 

It is nice that you cleaned the EGR :) I got to know EGRs in a rather detailed way on an EA82T by plumbing in T at the EGR valve vacuum source on the engine, ran that extension through to the cabin where I had another EGR valve in working order, drove around for days with my pinky jammed in to feel the vacuum actuating while watching a vacuum boost gauge.

 

Still to work out how a carby EA82 disengages the EGR at idle foot off throttle

 

better add a disclaimer : My dealings were with a series one EA82T and code 35 is for EGR solenoid being stuck ON or OFF

 

code 34 on Series one is a thermosensor ! But when playing with a later Spider version, did not wait for codes, just got in there and tested the two wires of the solenoids on a battery - both were stuffed, so replaced with used ones and is happy.

Just been reading series 1 factory manual and it details the workings of the egr valve - and they are all different between carb, mpfi, turbo and markets! They have different cut in temps and speeds for cut out between all the varieties.

 

But OP question was how to resolve without spending money ....check that solenoid :)

Edited by jono
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Still to work out how a carby EA82 disengages the EGR at idle foot off throttle

 

At idle...the Vac port hooked to the EGR is above the vacuum.

 

This is what;s called "ported" vacuum or "above throttle" vacuum.  The hole is physically above the flap in the throttle body, so when it's closed, there is no vacuum to EGR.

 

This is how it is on all cars.

 

Carbed subarus use a thermovalve mounted to the manifold to keep EGR off until warmed up.

 

FI ones do the same thing with a solenoid. 

 

But for both, once warm....the EGR gets vacuum from the port just above throttle plate, all the time once warm.

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Of course ! No vacuum above the throttle when closed ! Gloyale, you have explained the ported vacuum so simply :)

 

A closer look at an mpfi throttle body reveals the two port pipes to the front of the throttle body are right through to just above the throttle butterfly and I think both are the same, just plenty of ports to tap, and the one closest to the dizzy supplies "ported vacuum" to the dizzy and is T pieced right at the throttle body with other half of that T going to pollution cannister I think. I also think the second ported vacuum pipe on the turbo side/drivers side in RHD :) goes off to the EGR control solenoid.

 

I have been looking at factory manuals and Fuji had several different systems to control the EGR between markets. Switzterland and Sweden seem to be grouped together, Saudi Arabia and Australia sometimes the same, sometimes different pollution controls to the US market. Some markets are temp controlled and speed controlled

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