My ej20 is now running , but the ERG valve opens and closes , so the motor runs up and down .
can some one give me a run down what this valve does for the subaru motor & what may be the cause of this .

cheers seagull

God are you there ??

Hi Neil,

the EGR system is used to lower NOx (oxides of nitrogen) emission levels caused by high combustion temperatures. The EGR recirculates a small amount of exhaust gases into the intake manifold. The additional mixture lowers the temperature of combustion thereby reducing the formation of NOx compounds.

The system is equipped with an EGR valve, a backpressure transducer(BPT), and the vacuum lines connecting the various components. And the ecu of course. The BPT controlls the vacuum pressure to control the amount of EGR according to the engine load. The EGR valve is opened in response to the vacuum signal from the EGR control solenoid which is controlled by the ecu. The ecu detects engine driving conditions from the various sensors and translates the information into the correct On/Off EGR time.

Jörg

WOW , very interesting reading , so sitting there on idle would seem fine Jorg ?

It should not go up and down, or the valve should not open and close, like you say it does. Make sure it is all connected right. The little hoses and the wire to the ecu.
But maybe there is another reason for your idle to go up and down.

Jörg

hey seagull did you sort this one out?
my ej20 does the same thing idles up then drops down etc.
thanks
bob

I can't say for certain this is the case but this "hunting" is a by product of the ECU not knowing its base idle speed (well in other ricers anyway) basically the car is dropping the reves to low, detecting a potential stall then spooling up. I have fixed this a number of times for friends in various models of Honda. In the case of the Honda you generally remove a fuse (clock, interion light etc..) this lets the ECU know a change is comming, you disconnect the idle control valve, start the car and try to hold it at 1500 ish (bloody hard as it will be hunting like a mofo) for 10 seconds. At this point the ecu is now ready to take a new idle speed and this is set in the old fashion way with a screwdriver. Anyway thats how a couple of Jap brands do it so hit your Suby manual to get this sorted.

Stephen

Andrew sent me a ecu from his car , that sort of fixed the problem for a day & now its back with more issues .The ej20 n/a motor is a pain in the ass .due to little infomation with the ecu .Thanks to Jorge I got the Mistres running ( thanks mate ) .I will replace the ecu at some stage as its driving me mad or if Jorge come down at some stage I will get him to have a look + buy him many beers :party

are you sure it has an EGR valve?
Weren't they mostly on 80s carbie cars? I think your thinking of the idle control valve. It's adjustable you know, you can loosen the screws and turn it til the idle speed is ok.

come over and fix it for me Pete

Kinda sounds like the idle up valve. Mine did that when I first started it up but settled down after a while. Check for vac leaks as well. See what happens when you disconnect the idle valve plug? I wouldn't start adjusting the valve just yet as they are a biatch to get set again.

where is this idle valve plug located on the engine(I assume it's the same on al EJ20's)?

Looking at the engine from the front (cam covers) it's located on the right and rear of the inlet manifold. It has a tan coloured plug. The valve has a pipe/hose about 20mm that comes from it and goes into the intake down stream of the AFM. It shou;ld have A.B.C on the top of it I think.

[ Edited on 19-4-2006 by speedster356 ]