T.J. Posted July 10, 2007 Share Posted July 10, 2007 Well, I searched around and saw plenty of mis-fire threads but nothing that was specific to one side of the engine. Maybe one of you can help. I got misfire codes from our '03 Forester X 5mt (50,000miles) a few weeks ago. The car seemed to be running fine so I just checked the plug wire connections and the code went away not long after. During a camping trip this weekend the cel came back on and the car started running really rough. I limped it home low on power. So far I have used a spark checker on the ends of the plug wires and saw a spark on all four cylinders. So as far as I can tell, all of the cylinders are getting spark to the plugs. I pulled the plugs and found that both of the passenger side plugs were fouled and wet looking. They didn't seem oily, so I assume that the wet apperence is unburnt fuel. I replaced all four plugs w/ Bosch platinum plugs. I expected that replacing the bad plugs would get the engine running smoothly again until whatever the real problem was fouled them up again. Wrong. The car is still running rough w/ the new plugs. Is there anything you can think of that would cause both cylinders on one side of the engine to misfire like this? To cover some of the more obvious stuff: Oil looks fine. Coolant looks fine. The engine never over heated or smoked. The gaskets look good from outside. No leaks or other obvious signs that I have noticed. Any thoughts would be appreciated. I am going outside to check for bad vacuum hoses and electrical connections to give you guys a minute.:-p Thanks in advance, T.J. Quote Link to comment Share on other sites More sharing options...
nipper Posted July 10, 2007 Share Posted July 10, 2007 Soobies want the plugs that are recomended for them. If I remebr correctly its not the bosch. They are very picky about this and ignition wires. The spark system is a waste spark system. This means that 1-2 and 3-4 always fire together. Get the proper plug. If its running badly it should throw a code, get the code read. This will give us a better idea of what is misbehaving. nipper Quote Link to comment Share on other sites More sharing options...
gbrand Posted July 10, 2007 Share Posted July 10, 2007 A large vacuum leak in one side of the intake did exactly this to my old 80 wagon: On my 80 EA71 found out it ran on only 2 cyl on pass side. Changed plugs, had good spark, and compression. Still I could pull the 2 wires on drivers sied and car would idle the same. Pull pass side wires and car was stone dead. Finally a hot august night, and a 12 pack of determination set in-I finally decided the drivers side was starved for fuel. As this was a carbed engine, I did not worry about FI issues. I pulled a vacuum hose off the intake near the head, and put in a spray can tube hooked up to a can of starter fluid. Sure enough, as long as I gave a squirt on the can every 20 seconds or so the car would run, even with the 2 pass wires disconnected. Had big vacuum leak in some pollution control valve(anti backfire valve?) plumbed into intake manifold on drivers side that caused car to run on 2 cyl only, and a plug in it caused the car to run beatifully. Of course during all this dicking around the grease from CV boots past and transmisson leaks ignited on the overworked cat converter, the garden hose was lying near by or that might have been the last hurrah for the little blue wagon! Quote Link to comment Share on other sites More sharing options...
nipper Posted July 10, 2007 Share Posted July 10, 2007 Thats an idea. With the engine running, use a spray bottle filled with water and see if there are any RPM changes as you spray all over the engine. Pay close attention to the side with the bad plugs. nipper Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 10, 2007 Author Share Posted July 10, 2007 Thanks for the help guys. nipper, I will try the water bottle idea. I couldn't find any loose or deteriorated hoses or bad connections. I do see a little valve of some sort that looks like it is between the fuel system and the intake manifold on the passenger side. I wonder if that could be causing a condition similar to the one you are describing gbrand. Maybe it isn't associated w/ the fuel system. I need to look at it more closely. That will give me something to do after work tomorrow. Thanks again, T.J. Quote Link to comment Share on other sites More sharing options...
2X2KOB Posted July 10, 2007 Share Posted July 10, 2007 Wouldn't this be one of the ignition coils? Quote Link to comment Share on other sites More sharing options...
nipper Posted July 10, 2007 Share Posted July 10, 2007 Wouldn't this be one of the ignition coils? nope. They fire 1-2 3-4 with 1-3 and 2-4 on each side of the engine. nipper Quote Link to comment Share on other sites More sharing options...
2X2KOB Posted July 11, 2007 Share Posted July 11, 2007 nope. They fire 1-2 3-4 with 1-3 and 2-4 on each side of the engine. nipper OK, thanks for that, wasn't sure. Quote Link to comment Share on other sites More sharing options...
2.5GL Posted July 11, 2007 Share Posted July 11, 2007 I hate to say it, but it could possibly be burnt valves. Had one in last month with a constant misfire code for #3, replaced spark plug, injector, and spark plug wire, to no avail. Did a compression test and found that cylinder to be at 65 psi. Removed heads and inspected valves and the forward exhaust valve was indeed burnt. So, R&R valve(s) and HG and adjust lash, all was good... If a coil were to fail it would be front cylinders (1-2) or rear cylinders (3-4) It would be odd to have two injectors fail at the same time, so not to high on the likelyhood of that happening. Do a compression test, see what's going on inside the engine. For an extereme case, a leak-down test could be done to determine where the leak is after a compression test shows a low cylinder(s) Lewis Quote Link to comment Share on other sites More sharing options...
ron917 Posted July 11, 2007 Share Posted July 11, 2007 It would be odd to have two injectors fail at the same time, so not to high on the likelyhood of that happening. The injectors may be OK, but there may be a problem with the wiring on that side. Maybe the two injectors share a common ground or power wire? Quote Link to comment Share on other sites More sharing options...
nipper Posted July 11, 2007 Share Posted July 11, 2007 They do have a common power, but its common to all 4. Its sounding amore and more like a mechanical issue. Since the plugs are wet, we know fuel is getting in. The odds of two injects leaking are very low. nipper Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 12, 2007 Author Share Posted July 12, 2007 Thanks again for all of the input everyone. Todays update: I tried the water mist trick but the results were inconclusive. I pretty much soaked the engine spraying in different places (surprized I didn't short anything) but couldn't get the engine to react. I wanted to see what it would do, so I created a vacuum leak and hit it w/ the mist and the engine didn't seem to react. So I still don't really know what to expect if I had a vacuum leak. Hmmmfff. Does anyone know what this little valve is? It looks like it is mounted to the end of the fuel rail and has a vacuum hose leading to the intake manifold. It is toward the back of the passenger side. Looks pretty suspicious to me! Thanks, T.J. Pic: Quote Link to comment Share on other sites More sharing options...
nipper Posted July 12, 2007 Share Posted July 12, 2007 Thanks again for all of the input everyone. Todays update: I tried the water mist trick but the results were inconclusive. I pretty much soaked the engine spraying in different places (surprized I didn't short anything) but couldn't get the engine to react. I wanted to see what it would do, so I created a vacuum leak and hit it w/ the mist and the engine didn't seem to react. So I still don't really know what to expect if I had a vacuum leak. Hmmmfff. Does anyone know what this little valve is? It looks like it is mounted to the end of the fuel rail and has a vacuum hose leading to the intake manifold. It is toward the back of the passenger side. Looks pretty suspicious to me! Thanks, T.J. Pic: try creating the leak at the power brake booster and see what happens. Not all vacum lines are equal. Do a compression test. How old is the timing belt. nipper Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 12, 2007 Author Share Posted July 12, 2007 Yeah, I need to get a compression guage. Probably not untill payday though. The timing belt would be 50,000 miles old unless it has been replaced already. We bought the car at 40,000 miles. I have tomorrow off. I'll try the brake booster idea. Thanks. T.J. Quote Link to comment Share on other sites More sharing options...
ron917 Posted July 12, 2007 Share Posted July 12, 2007 Does anyone know what this little valve is? It looks like it is mounted to the end of the fuel rail and has a vacuum hose leading to the intake manifold. It is toward the back of the passenger side. Looks pretty suspicious to me! Pic: Fuel pressure regulator. If it were bad, all cylinders would be affected. Quote Link to comment Share on other sites More sharing options...
nipper Posted July 12, 2007 Share Posted July 12, 2007 Get yourself a cheap vacum gauge, lets see what that does. nipper Quote Link to comment Share on other sites More sharing options...
Cougar Posted July 12, 2007 Share Posted July 12, 2007 My guess on this trouble is the cam timing is off, at least on one side. It seems it would be kind of hard to do that though so I may be wrong. Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 12, 2007 Author Share Posted July 12, 2007 Thanks for the info ron. nipper, is a vacuum guage different from a compression guage? Same thing? My guess on this trouble is the cam timing is off, at least on one side. It seems it would be kind of hard to do that though so I may be wrong. Exactly. I'm sure the timing belt could effect one side of the engine like this, but the car was running great before this started. About a month ago it got 28mpg on a 380 mile road trip up Mt. Hood w/ the car fully loaded and a bike rack on top. I was impressed and took that as a sign that the engine was pretty healthy. No one has been in inside the engine to effect the timing belt location since we purchased it. Can it go out of adjustment? I was under the impression that if it went, it would just snap. T.J. Quote Link to comment Share on other sites More sharing options...
Cougar Posted July 12, 2007 Share Posted July 12, 2007 It could be a belt tensioner came loose and allowed the belt to slip. I am just speculating here. The fact that the engine was running so well and then turns bad makes me think this. Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 12, 2007 Author Share Posted July 12, 2007 It could be a belt tensioner came loose and allowed the belt to slip. I am just speculating here. The fact that the engine was running so well and then turns bad makes me think this. Ooooh. Do you think I could check this w/o removing the engine? Maybe just the radiator? Quote Link to comment Share on other sites More sharing options...
Cougar Posted July 12, 2007 Share Posted July 12, 2007 Doing a compession check will tell you if we are are the right track or not. If the timing is off the compression will be lower than normal. Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 12, 2007 Author Share Posted July 12, 2007 Great. I will swing by Harbor Freight and look for a cheap compression guage as soon as possible. Then what? remove all of the plugs and use the starter to turn the engine a certain # of times w/ the guage pluged in to one of the cylinders at a time? OT, I was born in Fairbanks. Didn't spend enough time there to remember anything. I have heard some stories from my parents though. Later, T.J. Quote Link to comment Share on other sites More sharing options...
Cougar Posted July 12, 2007 Share Posted July 12, 2007 When testing it is best to leave all the plugs in except the one you are working on, unless you want to see if there is a leak between the cylinders. We aren't concerned about that though. By cranking the engine a few seconds you should top out the gauge for a reading. I think you should see somewhere around 165-185 lbs normally but I'm just guessing. All cylinders should be within 10 lbs of each other if things are good. Quote Link to comment Share on other sites More sharing options...
T.J. Posted July 12, 2007 Author Share Posted July 12, 2007 try creating the leak at the power brake booster and see what happens. Not all vacum lines are equal. nipper Well, I pulled the big vacuum hose off at the brake cylinder. I started the car and could hear the air being drawn into the hose to the intake manifold. I could feel the vacuum w/ my finger over the hole in the end of the hose. I sprayed the end of the hose w/ our garden hose nozzle on the mist setting. I swear, the idle didn't change! :-\ Quote Link to comment Share on other sites More sharing options...
nipper Posted July 12, 2007 Share Posted July 12, 2007 Well, I pulled the big vacuum hose off at the brake cylinder. I started the car and could hear the air being drawn into the hose to the intake manifold. I could feel the vacuum w/ my finger over the hole in the end of the hose. I sprayed the end of the hose w/ our garden hose nozzle on the mist setting. I swear, the idle didn't change! :-\ Thats saying something in itself. hrmm do the compression test and the vacume gauge thing and let us know what happens nipper Quote Link to comment Share on other sites More sharing options...
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