nipper Posted June 9, 2009 Share Posted June 9, 2009 hrmmmm Did you do a wet and dry compression test. Drys is just what it says. Wet means you squirt some oil in the cylinder and repeat the test and see if the numbers go up. If they do you have bad rings, if they dont (assuming the numbers are low) its valves. The fact that the compresion got extreemly high (too high) means either you did something odd, or there is an timing issue. Subarus NEVER get that high a compression reading, as max is 180-185 for a healthy engine. The good news out of those numbers is that your head gaskets are good. The numbers themselves are even so the compression is balanced. Also there is no shame in throwing in the towel and letting a shop look at it. I am still going with your engine timing being off. Go to www.endwrench.com and look in the archives under engine. Read the section on timing belts. I need to know EXACTLY what the vac gauge is doing and what numbers it is "flucuating" on a healthe engine the needle is fairly smooth, so smooth in fact it is steady. I think the key to this issue is you telling me exactly what that gauge is reading. You said you swapped out coil packs at one point? nipper Quote Link to comment Share on other sites More sharing options...
211 Posted June 9, 2009 Author Share Posted June 9, 2009 (edited) hrmmmm Did you do a wet and dry compression test. Drys is just what it says. Wet means you squirt some oil in the cylinder and repeat the test and see if the numbers go up. If they do you have bad rings, if they dont (assuming the numbers are low) its valves. I only did dry compression test. The fact that the compresion got extreemly high (too high) means either you did something odd, or there is an timing issue. Subarus NEVER get that high a compression reading, as max is 180-185 for a healthy engine. The comp tester I borrowed is pretty old, it's not a needle gauge like you'd get at NAPA today, it's a horizontal gauge with a bar that moves left to right (think scroll chart). I don't doubt that the overall readings were off by a bit. My faith in the accuracy of the gauge is that all the readings were close to the same. The good news out of those numbers is that your head gaskets are good. The numbers themselves are even so the compression is balanced. Agreed... and as mentioned, I trust the gauge only because the readings were the same, not based on what the needle read (I know this just muddies the waters, but this comp tester is all I had access to at the moment). I need to know EXACTLY what the vac gauge is doing and what numbers it is "flucuating" on a healthe engine the needle is fairly smooth, so smooth in fact it is steady. I think the key to this issue is you telling me exactly what that gauge is reading. I go back to work tomorrow, but when I get home I think I'll post a video of the vac gauge at idle and when I increase throttle. You said you swapped out coil packs at one point? nipper Swapped coil packs out, yes, with the coil out of my neighbors 2k OBW. It did not make a difference. Although, my coil 'fails' according to the test procedure found in the Chilton manual; interestingly enough though, I compared the resistances of my coil to the neighbors (before I had a manual to reference)and they were the same. So either the book is wrong or my neighbor has a bad coil he doesnt' yet know about. I'm close to throwing in the towel. I'm just really stubborn (no.1) and no. 2, at this point, with respect to all the diagnosing I've done so far I feel the shop will only do what I just did this past weekend and charge me to swap out components until they 'fix it'. Which is what I could do if I had a replenishing bank account. And I've read more endwrench articles in the last three days than I have since I've owned this car. I'll read again on the timing, but I'm pretty sure Ive followed each of the guides to a T. One thing I have learned in all this is Subaru's are actually pretty simple compared to some vehicles... I'll post a video of the vac gauge tomorrow and post a link. Also, I want to thank everyone for they're efforts in helping me with this; Nipper you especially- you're influence on these boards does not go unnoticed Edited June 9, 2009 by 211 Quote Link to comment Share on other sites More sharing options...
nipper Posted June 9, 2009 Share Posted June 9, 2009 The ONLY vac gauge readings that matter are the ones at idle for the most part. A video is not needed, just tell me what it is doing Yes you are stubborn. i dont always trust the coil tests as they are not always correct. Have you taken a meter to your plug wires yet? and not ALL shops are crooks and thieves. That really irritates me when someone makes a blanket staement like that. i will hold my tonhue from really sayng what i feel, but so far.... never mind i will just piss people off. If you dont like your shop find another one. Right now your not doing any better for what may be a simple issue that you at your expierience level can not comprehend. nipper Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 9, 2009 Share Posted June 9, 2009 211, I hope you don't mind, but I'm going to change the order of what you wrote so that my comments are more relevant. [...]The book says to expect a primary resistance of 0.6-1.3 ohms between pins 1/2 and 2/4 (if you're looking at the coil's 4-pin connector from the passenger side, pinout is right to left; pin 1 being closest to the radiator, pin 4 being closest to the airbox). My coil reads 'open' (oL) at both these connections!?!But now I'm ultra confused because my neighbor's coil had the same readings and my engine ran the same with his coil swapped in. I've found several errors in Subaru literature (both factory and other) concerning resistance measurements of coil packs. Specifically, the primary can't be tested with an ohmmeter on packs having an integrated igniter. Did a vacuum check per manual; readings were rock solid at 20'' fully warmed up at idle. However, as soon as I touched the throttle to increase rpms it would flick back and forth +/- 3-5''. But I could also hear and feel the engine 'missing' while increasing the rpms. Once I dropped to idle it stabilized at 20''. [...] I also did what Nipper suggested which was disconnect each plug wire one at a time and note any fluctuation in idle. Cylinders 1, 2, 3, when pulled made the engine run rough(er) than normal. Cylinder 4 made no change in engine idle. Also, the spark coming from the boot of the other three wires was MUCH stronger. I'm talkin' a 1''; spark though air between the boot and a ground. Cylinder 4, in order to see the spark I had to physically touch the tip of the boot to ground, even then it was weak. Also, the spark would miss every few revolutions. Insufficient spark can cause a misfire that doesn't show up at idle, but will at even slightly higher RPM. That can be evident as a rhythmic drop in the vacuum reading each time the ''bad'' cylinder misfires. There are things other than ignition problems that can cause a similar vacuum drop, but the weak spark from the #4 wire you mentioned is something to further investigate. ...coil? The coil would have been my concern as well, if you hadn't already swapped it out for one that assumedly is known to be good. If I read things correctly, you also already swapped ignition wires. I'm beginning to wonder if the ECU is getting a particularly weak pulse for cylinder #4 due to either a bad position sensor or damaged reluctor. Quote Link to comment Share on other sites More sharing options...
211 Posted June 9, 2009 Author Share Posted June 9, 2009 (edited) The ONLY vac gauge readings that matter are the ones at idle for the most part. A video is not needed, just tell me what it is doing nipper At idle the vacuum gauge reads a steady 20" fully warmed up. There is a TINY bit of needle-flicker at 20" but it's barely perceptible. And yes, I took a meter to the spark plug wires; they ohm out well within the norm. If I read things correctly, you also already swapped ignition wires. I'm beginning to wonder if the ECU is getting a particularly weak pulse for cylinder #4 due to either a bad position sensor or damaged reluctor. Correct, I swapped igition wires from the neighbor's car as well. One of the powertrain engineers here at work suggested a TPC or faulting ECU as well. He's not a "subaru guy" though... he just knows engines in general. Edited June 9, 2009 by 211 Quote Link to comment Share on other sites More sharing options...
Hendrik Posted June 9, 2009 Share Posted June 9, 2009 I had a similar thing , nearly new plugs , but if the other side`s plug is dirty\faulty , your number 4 will not work as normally. Plugs are cheap , better replace all. regards and succes. Quote Link to comment Share on other sites More sharing options...
211 Posted June 9, 2009 Author Share Posted June 9, 2009 I had a similar thing , nearly new plugs , but if the other side`s plug is dirty\faulty , your number 4 will not work as normally. Plugs are cheap , better replace all. regards and succes. Bran-new plugs somewhere back on page 1 (installed them Friday), they have zero miles on them and are otherwise unused except for start up and idle during these troubleshooting steps. Quote Link to comment Share on other sites More sharing options...
nipper Posted June 9, 2009 Share Posted June 9, 2009 For now i am going to go with engine being healthy, and hold off on the valve timing. That would have shown up in the vac gauge. Vac gauges are an underrated and oft overlooked tool, but they can tell you a lot of things. On the crankshaft there is a special tooth geared. This is used for the crank sensor, which in turn sends a signal to the ECU to fire the plugs. If that is dmaged, which can happen, it will make for a weak spark. It may be possible that we are assuming the bright spark is correct, and the weak one is the issue. This is a waste spark system, meaning the plugs are fired in pairs. Electricity likes the path of least resistnce, so the weak spark may not be the suspect side. There may be a shoort on the strong spark side (not allowing for the good side to get full voltage). Like i said there is only so much that can be done over the net, and sometimes the need for an on-hands professional is required. nipper Quote Link to comment Share on other sites More sharing options...
211 Posted June 9, 2009 Author Share Posted June 9, 2009 Ding-Ding-Ding... I'm throwing in the towel guys! Called up a reputable auto shop which I've done buisness with in the past. They've resurrected my wife's dodge intrepid from the dead on many occasions. Talked at length with one of the techs and he assured me they have a "Subaru Master" on site. I feel pretty comfortable bringing my car in. At this point I need to start throwing money and parts at it. I might as well take the alternative and throw money at the pro's. My appointments a week out though. I suppose in the meantime I can do a visual inspection of the crank pulley's reluctor ring, make sure all its teeth are accounted for. Quote Link to comment Share on other sites More sharing options...
Cougar Posted June 10, 2009 Share Posted June 10, 2009 How about running some Seafoam through the engine to see if that helps with this. If that doesn't do the trick I would suggest the shop look at the firing pattern with a scope and see what that looks like on the screen. Quote Link to comment Share on other sites More sharing options...
211 Posted June 17, 2009 Author Share Posted June 17, 2009 It ended up being a bad Fuel Injector in #4. The shop did a battery of tests; the signal coming from the ECU is good, there's some electrical issue once the signal gets to the injector though. They're replacing the injector and will connect it to the scope again to make sure the waveform pulses all jive with eachother. ...500$ later. We were sooooo close!!!! I guess I was close to swapping injectors before I threw in the towel, but my fear was I'd break one or do more damage and still not know what the root cause is. Quote Link to comment Share on other sites More sharing options...
unibrook Posted June 23, 2009 Share Posted June 23, 2009 Glad they found the issue. Thanks for reporting back here with the solution. Too often people don't bother. Quote Link to comment Share on other sites More sharing options...
Mikevan10 Posted June 23, 2009 Share Posted June 23, 2009 "Glad they found the issue. Thanks for reporting back here with the solution. Too often people don't bother. " AMEN to that! Another tricky one though. Based on your observation that cyl. 4 had a drastically weaker arc than cyls 1,2 and 3 I would have been looking only at ignition realted stuff, not fuel feed. Anyone care to account for why one cyl. would (at least appear to) have a noticibly weaker zapper? Mike V. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 23, 2009 Share Posted June 23, 2009 (edited) Another tricky one though. Based on your observation that cyl. 4 had a drastically weaker arc than cyls 1,2 and 3 I would have been looking only at ignition realted stuff, not fuel feed. Anyone care to account for why one cyl. would (at least appear to) have a noticibly weaker zapper? Mike, I'm not sure I can rise to your challenge to ''account'' for the apparently weak spark to #4, so how about some conjecture? If you reread the last paragraph of my post #29 in this thread, I was wondering whether the ECU was providing a compromised ignition pulse for #4. The ECU determines EREV (engine speed) from pulses developed by the crank sensor and reluctors on the sprocket, and uses that data to influence ignition timing and dwell. If the ECU detects a drop in EREV a sufficient number of times after a particular cylinder is supposed to have fired, it ''assumes'' that the cylinder is misfiring and sets a code. Now for the conjecture -- perhaps the detected drop in EREV causes the ECU to markedly change the ignition dwell for the affected cylinder, thereby affecting the spark intensity. Edited June 23, 2009 by OB99W Quote Link to comment Share on other sites More sharing options...
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