Here's a mystery for you!

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  #1  
Old 11-21-04, 05:34 AM
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Here's a mystery for you!

Hello all. The problem is with a 1992 Subaru Loyale 4wd wagon. It has a 1.8L engine, single point fuel injection. It has approximately 179K miles.
Over the past end on the summer up to now I have been getting a check engine light on startup. Didn't seem to be a big deal at the time as it didn't seem to cause any driveability problems. But, with the colder weather coming it now will not stay running, when cold, unless I keep reving the engine. Once it warms up a bit it will run as it always has.
As far as the CEL (check engine light) goes, I know that the code will display if you pull out the kick panel under the drivers side. So, I checked it out and it read a egr temp. sensor or circuit problem. THis would be alright, but, as it turns out this car is a Federal Emissions car and not a California Emissions car so it should not have this code stored.
The next step was to take it to a reputable Subaru dealer in the area and have it checked out there. Well they pretty much came up with the same results that I did with the egr thing. There was one tech. that had been there for over 28 years and he had never seen anything like this either! The only thing that they could suggest was to pick up another ECU and swap it out and see if the code goes away. Its possible that this car may not have the original ECU in it I guess.
So this is where I am at right now, I am really no closer to diagnosing this problem now than where I was a couple of months ago.
One other note was that a local mechanic suggested that I remove and clean the egr valve. I went ahead and did that and also checked the associated switches just to be safe and it didn't seem to make any difference.
It acts to me just like the old carburated cars when the automatlc choke isn't working right, like it wasn't getting a rich enough mixture on startup.
Well I've rambled on enough, but, I wanted to give you as much info. as I could to see if you could come up with anything because I frankly have run out of options. Thanx in advance for any advice you can supply.
 
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Old 11-21-04, 07:18 AM
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You might want to try getting the part number off of the ECU and checking it with the dealer to see if it is what its supposed to be.

www.subaru-svx.net/photos/files/6evil9/12757.pdf
Check code 55 on here (fig. 44) all the way at the bottom. It shows the wiring diagram for the EGR temp sensor. I realize your car isnt supposed to have this on it, but maybe it does. Check to see if you have a wire on that pin of the ECU. If I am reading that diagram correctly, then the only difference between the CA vehicle and a non-CA is that one wire in regards to the EGR temp sensor and that it actually is equipped with one. But the diagram could be misleading.

Hope this helps.
 
  #3  
Old 11-21-04, 12:06 PM
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Hey pt thanks for the input. I tried the link,but, I couldn't get it to open. As far as the temp. sensor goes I even went ahead and ordered one from my local NAPA store just to see if I could find it on this car, I couldn't. The store clerk there has been having a similar problem with his Subaru and he was just as curious as I was as to find out what this particular problem is.
I am not 100% sure where the ECU is on this car. THe dealer said it was either under the seat or in front of the passenger side kick panel. Makes me a little apprehensive if he couldn't be sure of where it is.??
Oh well I'll keep on plugging away.
 
  #4  
Old 11-30-04, 04:35 PM
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Update

Well I thought I'd close out this thread. For anyone that has this problem in the future, what it turned out to be was a fuel injection coolant thermosensor. I guess what was happening was that when you first start the car the F.I.C.T increases the amount of fuel delivered to the cylinders. The sensor was telling the ECU that the motor was warmed up and not cold, so, no extra fuel.

As far as the bogus code, I guess it is called a "phantom code". Where there is no specific code for that sensor of that year, the ECU sensed that there was a problem, it just didn't know exactly where.

There is a really good website where I actually obtained most of my good info. I'm not sure if I can list it here, but, if you care to you can P.M. me and I'll be glad to provide you with a link to it.
 
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