'85 Subaru engine problem

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  #1  
Old 07-29-03, 08:35 AM
jtackett
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Question '85 Subaru engine problem

I've got an odd problem. '85 Subaru GL (non-turbo, non 4 wheel drive, 1.8 eng.)-I have one cyl. that does not run. I have good compression (a couple pounds higher than the others-approx. 180). I have plenty of spark (new wires & plugs). I even changed wires & plugs from other working cyl. & still nothing. I took the valve cover off to verify that the valves were ok & they seem to be fine (turned the engine over while watching). I replaced the timing belts (one broke a couple of months after that cyl. quit running) & still no change. The only things that I can think of that will keep a cyl. from running is: 1)No compression 2)No spark 3)No fuel. Am I missing something? Any ideas would be GREATLY appreciated. Thanks, Jeff
 
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  #2  
Old 07-29-03, 09:02 AM
Joe_F
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What are the actual compression readings on each cylinder? Sounds like a bad cylinder.
 
  #3  
Old 07-29-03, 09:08 AM
jtackett
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The readings were from 175 to 179. The 179 being the one that doesn't run. Jeff
 
  #4  
Old 07-29-03, 09:21 AM
Joe_F
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Swap a spark plug and wire over that cylinder. Let's see if the problem transfers. You may have a bad spark plug wire or problem in the distributor cap (happens even with new parts).
 
  #5  
Old 07-29-03, 09:29 AM
jtackett
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"I even changed wires & plugs from other working cyl. & still nothing."

That was one of the first things I tried, this one really has me stumped.

Jeff
 
  #6  
Old 07-29-03, 10:34 AM
Joe_F
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If the timing belt broke it MAY have damaged a valve that's it's causing a dead/late cylinder.

Check the Gates website to make sure that this engine is not interference. The wall chart I have here at work says it's non-interference, but you could have still bent a valve.
 
  #7  
Old 07-29-03, 02:33 PM
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Did you check for spark on the dead cylinder?If so and you have spark check for a vacuum leak at the intake for that cylinder.I don't remember if these were multiport but if so you may have a bad injector.Years ago my cousin broke a belt on his Subaru and I replaced both.Still wouldn't start he said it ran fine before the belt broke,air filter was clogged.Replaced the filter ran great.Very sensitive MAF sensor.Your compression is too even for valve problems or broken rings.Good Luck.
 
  #8  
Old 07-29-03, 03:13 PM
jtackett
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It's not multiport, so that's not it. That cyl. hasn't ran for a couple of months. The belt just broke a week or so ago. If I had a bent valve I wouldn't have good compression would I? I also can see the valve move all the way in & out when I turn it over manually. I do have spark on that cyl. also. As far as the vacuum leak goes, I hadn't thought of that. How could there be a leak on just one cyl.? Head gasket? Wouldn't a compression test show a problem there? Thanks, Jeff
 
  #9  
Old 07-29-03, 03:53 PM
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Not a headgasket leak you would have low compression.Intake manifold or hose related to that cylinder causing it to be lean, too much air in the cylinder won't fire.Put a vacuum guage on a central manifold port and see if the needle bounces rapidly.If the needle bounces rapidly you may have a weak valve spring.If you don't have a vacuum guage do a running compression test and post the results.
 
  #10  
Old 07-29-03, 07:37 PM
Joe_F
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If you don't have a vacuum gauge, Autozone can rent you one free of charge through their tool rental program. Use the right gauge for the job .
 
  #11  
Old 07-30-03, 08:31 AM
jtackett
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Thanks guys, I do have a vacuum guage (somewhere) & I'll check that as soon as I find it. Davo, I'm not sure what you mean by a "running compression test". Please explain. Thanks, Jeff
 
  #12  
Old 07-30-03, 08:39 AM
Joe_F
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Arrow

Hook up the vacuum gauge and post your results. You may have a late valve or a broken spring as Davo suggested.
 
  #13  
Old 07-30-03, 08:43 AM
jtackett
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Will do! Thanks, Jeff
 
  #14  
Old 07-30-03, 02:54 PM
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A running compression test means you start the engine and note the reading for each cylinder.
 
  #15  
Old 07-30-03, 03:46 PM
jtackett
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Gotcha! The name was pretty self explanitory in this case!! Thanks, Jeff
 
  #16  
Old 07-30-03, 06:44 PM
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Hello, I have been reading your posts on the Subaru and have a couple of questions. I have been running Subs for a few years and have learned some about them.
First, did you install the belts yourself? And if so did you have a manual? THe reason I ask is that it is real easy to get screwed up on your timing, especially in regards to your distributor.
I hate to see anyone struggle with these because" usually" it ends up being something simple that was overlooked during the repair job. Rarely is it something that is a major wrong.
 
  #17  
Old 07-30-03, 07:56 PM
jtackett
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Thanks for the input, I've had (3) Subaru's myself starting with a '74 DL. I know my way around them pretty well but have never come across a problem like this. The problem came up a couple of months before the belts were changed so that couldn't be it anyway. I've changed timing belts on this one before & twice on my others so I've got it down pretty good. Thanks, Jeff
 
  #18  
Old 08-01-03, 05:41 AM
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I find it odd that this engine was running very well on 3 cylinders. It must have been real bad on the hills. I guess if you are certain that you have the timing right and it looks like your compression is good then the only thing left is fuel.
Is this fuel injected? I know that my 82' had a Carter/Weber carb. on it and the 88' I had was single point fuel injected and I'm not sure where the change took place.
Please keep us posted, I'd be interested to see just what this turns out to be.
 
  #19  
Old 08-01-03, 05:47 AM
Joe_F
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Arrow

I believe around 1985, depending on the model, Subaru went over to fuel injection.
 
  #20  
Old 08-01-03, 06:06 AM
jtackett
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I rebuilt the carb. in the mid 90's so it is most definitely carbureted. This is the first new car we ever bought (the first of only 2) & is on it's second teenager-my son is a senior in high school. I hope to be abel to check the vacuum this weekend. I'll keep you posted. Thanks, Jeff
 
  #21  
Old 08-01-03, 06:19 AM
Joe_F
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Correct, but SOME Subaru models this year were FI to my knowledge---for example the XT Series had FI.
 
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