Garrett Posted January 20, 2009 Share Posted January 20, 2009 this is a 1993 subaru loyale with an ea 82 engine automatic. does anybody know how to test the EGR or the EGR coil? i pulled the hose off the top and plugged it and looked down the hole while reving the engine and the shaft didn't move. Does this mean its not working or is there another test? Quote Link to comment Share on other sites More sharing options...
Skip Posted January 20, 2009 Share Posted January 20, 2009 Mr Garrett sir, the problem is the solenoid valve that controls the vacuum to the EGR valve. The rubber vacuum line leads to this solenoid valve. Very common problem, many posts on different fixes. Many use a solenoid of the same type from a late 80's Honda or Toyota , some wire a 35 ohm resistor to "fake out" the ECU. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 20, 2009 Share Posted January 20, 2009 Here's how I fix it: http://home.comcast.net/~davidtief/solenoid.html To test the solenoid, unplug it from the harness. Apply 12VDC across the 2 pins. If it clicks, it is ok. It most likely won't. The ECU only can tell if the solenoid has failed open circuit. 1 Quote Link to comment Share on other sites More sharing options...
Garrett Posted January 20, 2009 Author Share Posted January 20, 2009 This one doesnt have any vacuun lines, it just has one wire running to it. I took it out and cleaned all the carbon out of it, and I cant see if its working or not. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 21, 2009 Share Posted January 21, 2009 This one doesnt have any vacuun lines, it just has one wire running to it. I took it out and cleaned all the carbon out of it, and I cant see if its working or not. Ok, something isn't correct here. The stock Subaru solenoid is the rusty part in the picture on my web site. http://home.comcast.net/~davidtief/solenoid.html The EGR valve is bigger, round, mounts on the rear of the intake manifold. It can get carbon built up on the internal valve bits. 2 bolts hold it on. It has 1 vacuume hose, that goes to the Solenoid. Can you post a picture of the item you want to test? 1 Quote Link to comment Share on other sites More sharing options...
Skip Posted January 21, 2009 Share Posted January 21, 2009 Are you from Cordova as in Spain? Just down the E-5 from El Carpio? We never got an electronic EGR as you describe. DaveT is spot on with his recommendations. Have you checked this device for it's electrical resistance? Our ECU's are pretty dumb, they look for a certain resistance, if the devise shows an open (infinite resistance) it light the engine check light. Quote Link to comment Share on other sites More sharing options...
rickyhils Posted August 12, 2018 Share Posted August 12, 2018 (edited) I just fixed my 1991 Loyale ECU. New EGR solenoid was still showing code 34. All wire paths checked ok. The fix is this: Open Hitachi ECU box and go to the first 10 pin transistor IC array. The EGR solenoid wire returns directly there. IC It will be UPA1478H. ECU now good to go. Other symptom I had showed 7 volts at EGR solenoid connection (ignition on /engine off) . Should have been 12 v. Edited August 12, 2018 by rickyhils Quote Link to comment Share on other sites More sharing options...
DaveT Posted August 12, 2018 Share Posted August 12, 2018 Good job. That's the first time I've seen or heard of the ECU causing this problem. Quote Link to comment Share on other sites More sharing options...
rickyhils Posted August 12, 2018 Share Posted August 12, 2018 More Re: ECU story. It is ironic that the CEL remained off for last weeks smog test. My electronics guru friend suspects that when old EGR solenoid when bonkers with high and low ohm readings it also created voltage spikes that messed up the ECU. With no Hitachi schematic available, opening ECU case showed EGR solenoid return wire going directly to that UPA1478H which is what pulls down to ground the 12v reference input that first is fed into the EGR solenoid. It was only allowing 7 volts at solenoid connection. And, I am in California. I failed smog last week with CO% at 0.90 (max allowed is 0.66 ). I addressed what my mechanic diagnosed, and I put new CARB approved cats welded on for $440.00 parts and labor. Cat was clogged due to a coolant leak into cylinders and overheating. Problem was that double horseshoe coolant gasket under the throttle body. At one point driving up a grade at highway speed gave symptoms of fuel pressure problem, but was clogged cat. I have to say the exhaust smell a lot better now. When I pass smog next week I will investigate rebuilding an extra EA82 (SPFI non-turbo) . Car is at 310k miles. I will not see it go to the crusher till at least 400k (or 500k?) . 1 Quote Link to comment Share on other sites More sharing options...
rickyhils Posted August 12, 2018 Share Posted August 12, 2018 And Dave T. Thanks for your reply. Quote Link to comment Share on other sites More sharing options...
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