So, I have been observing some hesitation/stumbling/lack of power on acceleration and a check engine light. Reads code 34 (EGR valve). After doing some reading and tests, it doesn't appear to be a vacuum leak and the valve moves fine. This site says if it opens too soon or too much, it can cause these issues:

 

http://www.automotiveforums.com/t164450-what_is_egr_valve_and_symptoms_of_faulty.html

 

Now, I plugged the vacuum hose to the EGR valve with a golf tee. Engine runs significantly better. Now, apparently, with the EGR permanently close, this can cause knock due to the now-higher temperatures in the combustion chamber. I'm not enthused about spending 70 bucks on a new EGR valve, but I don't want to cause the engine to start knocking, nor do I want to live with the awful performance. Is there a switch I can replace, or do I have to replace the whole valve?

Edited June 29, 201213 yr by JEBalles

for me it wasn't the EGR valve itself, it was the antiafterfire valve that was attached to it. that piece just cuts down on the pop when your letting off the gas at higher rpm.

 

the EGR is only supposed to kick in at cruising speeds when your light on the throttle. Detonation (the knock) is primarily when the engine is under load. closing off the EGR shouldn't cause any detonation unless there are other factors. doesn't mean your car wasn't tuned with a leaking egr and will need retuned to correct it.

i have played with EA82T EGR's. They have a solenoid or two depending on manifold, that control the vacuum on mpfi's anyway. Carbies also use same not sure what is over ride control if no ECU. But they are designed to only work with vacuum , and there is not much vacuum around when you are after power so the knocking thing is debunked I think. My playings with found operated only betwen about 1 to 10 inches of vacuum. I T pieced a vac linein caboin to a spare EGR and held little finger in that GR to feel when it worked.

 

ECU controlled are also supoosed to cut EGR out until at operating temp and not at idle, nor op above 45kph !

 

Yours might be gunked up and not sealing closed properly.

The solenoids can stick open or closed and easily tested on a battery to hear for healthy ones clicking in and out

Now, I plugged the vacuum hose to the EGR valve with a golf tee. Engine runs significantly better. Now, apparently, with the EGR permanently close

 

Did you even have to plug it? Isn't the EGR valve opened by applying vacuum? It's ordinarily always closed, so I'm assuming the vacuum opens the valve.

 

Reason I ask is I have a faulty EGR solenoid and was just thinking about doing what you mentioned because I have surging while accelerating and have been wondering if it's the EGR...

 

After going out and taking a look, it's a real simple system. There's a hose leading to the solenoid from the manifold, there's the two wire electrical connector that activates the solenoid, and then there's the hose coming from the back-side of the solenoid that goes straight to the EGR valve, so if anything it seems you should plug the hose coming off the manifold so you're not losing any vacuum.

This is on my SPFI ea82 though, I haven't looked at the EGR system on my carb'd ea82, though I should, considering it's parked. If it's a similar system (though I doubt it, carb'd ea82 doesn't have an ECU, correct?) I'd just snatch the solenoid off my GL and throw it on the Loyale.

 

Just my .02.

... Now, I plugged the vacuum hose to the EGR valve with a golf tee. Engine runs significantly better. ...

 

 

Well... The EA82 engine has a faulty EGR design and Subaru knew that, so they eliminated the EGR pass on the Third Gen of EA82 Heads.

 

(There are Three Gens of EA82 Heads, more info & Pics, ~► Here)

 

So, since my Subaru "BumbleBeast" Runs on the Third gen Heads, I just Removed the EGR stuff from the Intake, as you can see pics, ~► Here.

 

And I haven't had any Issues related to the EGR.

 

So I Kindly suggest to let it Unplugged, just close (cap) the vacuum hose that goes to the EGR valve, to prevent a vacuum leak and Try your subie like that for a while; if you don't like the Behaviour, you can either reconnect it or buy a brand new EGR for 70 Bucks... but it worth the Test.

 

Kind Regards.

Yeah, that's the hose I plugged.

 

Did you even have to plug it? Isn't the EGR valve opened by applying vacuum? It's ordinarily always closed, so I'm assuming the vacuum opens the valve.

 

Reason I ask is I have a faulty EGR solenoid and was just thinking about doing what you mentioned because I have surging while accelerating and have been wondering if it's the EGR...

 

After going out and taking a look, it's a real simple system. There's a hose leading to the solenoid from the manifold, there's the two wire electrical connector that activates the solenoid, and then there's the hose coming from the back-side of the solenoid that goes straight to the EGR valve, so if anything it seems you should plug the hose coming off the manifold so you're not losing any vacuum.

This is on my SPFI ea82 though, I haven't looked at the EGR system on my carb'd ea82, though I should, considering it's parked. If it's a similar system (though I doubt it, carb'd ea82 doesn't have an ECU, correct?) I'd just snatch the solenoid off my GL and throw it on the Loyale.

 

Just my .02.

Plugging that hose seems to have helped my chugging and surging issues, as well. Hopefully I'll see a MPG bump! This was on an SPFI.

I installed a 2 barrel manifold on my EA81 engine with a Weber.

 

I removed and caped the small line and removed and used a 4 inch piece of 1/2 inch heater hose plugged to kill the large line.

 

Texasjack