bsheaffer Posted June 21, 2020 Share Posted June 21, 2020 Hewwo Subawoo, again. Some time ago now, I posted an issue Just looking for some general guidance as my ‘15 Legacy 2.5i limited, was acting like it was not firing right, when idling for a long time. A few months ago we changed spark plugs as I was noticing it more (Subaru OEM) but that only seemed to amplify the issue; and would actually “misfire” at low rpm while driving. I’ve been running cleaner and Shell Premium since March as a general “maybe things are gummed up” Now, a couple days ago I was heading for boys day out, as I was getting on the highway and getting up to speed it really begun to chug hard and not just act like a small misfire, but like the cylinder was on a defibrillator clinging to life. For once it was enough to light up my dash like a Christmas tree, throw a code and put me on the side of the road. I limped it down the road to a more safer place to stop as it would come back clear all lights and even the check engine code, be fine and die again lighting everything back up. I keep a scanner in my car and was happy to have a code, but unhappy at a major fault. P0302 Cylinder 2 Misfire detected. It only does it at mid to low rpm, while not fully warm, now. Normally I’d say maybe coil pack as spark plugs were changed, and not really exhibiting any symptoms of a head gasket issue. But recently, before the major misfire about a couple weeks a relay started going nuts somewhere in the driver fuse/distribution area, I haven’t figured out witch one, it just randomly clicks, and while it was really screwing up the other day it was going really crazy during. It sounds Link to comment Share on other sites More sharing options...
gathermewool Posted June 21, 2020 Share Posted June 21, 2020 As you mentioned, the coil would be my first suspect. You need to find out which relay is going “nuts”. Have you checked the fuel pump relay? '15 FB25 Magnatec 0W-20 + FU filter (70,517 miles) RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where Link to comment Share on other sites More sharing options...
bsheaffer Posted June 21, 2020 Author Share Posted June 21, 2020 It’s definitely one of the 5 relays on the main interior box, all that is there is IG1, IG2, starter, accessory1 and accessory2. Can pull up my service manual and see if it’s attached to any of that, but also if was a fuel pump issue it wouldn’t just be consistently only one cylinder going. I did take a look the other day, and the coil packs only have a fuse, the ECM, and ground. So again, if that relay was powering the ECM, it would be more then #2. Not a loose connector because pulling it off results in a “circuit open” code. Everything does point to the coil pack, but the relay failing at the same time & really going crazy durring the misfires, makes me want to think there is something to do with that. Dono.... why I’m just seeing if there any ideas... Link to comment Share on other sites More sharing options...
bsheaffer Posted June 21, 2020 Author Share Posted June 21, 2020 Just did the op test with a wire, it’s acting completely fine, but it’s always intermittent, while driving or after a few idel hours. And I don’t feel comfortable enough to let it run on 3 cylinders for a couple hours with a wire sparking. It’s not missing a beat and it’s nice and strong.. if it wassnt a $100 part (subaru oem) I’d be a bit more happy to buy and try.... Link to comment Share on other sites More sharing options...
gathermewool Posted June 22, 2020 Share Posted June 22, 2020 You’re talking about coil (RE: 100 part), right? Just swap two coils and see if the the issue follows. '15 FB25 Magnatec 0W-20 + FU filter (70,517 miles) RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where Link to comment Share on other sites More sharing options...
bsheaffer Posted June 22, 2020 Author Share Posted June 22, 2020 Yeah, well next thing to try. Fortunately it’s #2 and not #4 because that’s the absolute worst to get to Stupid boxer.... jk love u... but seriously hate you. These are the times I’m happy I don’t have the 6 cylinder... Link to comment Share on other sites More sharing options...
bsheaffer Posted June 23, 2020 Author Share Posted June 23, 2020 So... definitely not coil pack. with a flip flop its still the same cylender but it seems to get progressively worse as I tough it. After the flop and a start it was idling bad. I decided to pull the plug to the injector and it made little to no difference to running bad. Ive moved on to a possible fuel injector issue. I did check the resistance per the service guide and it reads 12.1 +- .2% at 69 degrees and the manual says 12 ohm at 68 degrees (yes obviously the engine is cold, 24 hours since ran cold, I'm not an idiot) So I'm going to call that a win.I have an oscilloscope does anyone know what the signal should look like? I'm guessing a nice pwm signal. Im sure I could get it for another to compare but that takes me to my next point THAT *bad word* RELAY... I'm not giving up that it has something to do with it. scouring all the schematics and wiring diagrams none of those internal relays have much to do with the injector, yes, it does power the ECM but that failing would cause more then just one injector? Its weird because I don't always get flashing check engine and just yesterday with testing the vehicle dynamics light (one that flashes when slipping) came on solid. It left no usable code... that relay is screwing with something and it has to be part of the issue... there is no possible way its not part of it... In a bit I'm going to flip flop some relays to see what that does... Link to comment Share on other sites More sharing options...
gathermewool Posted June 23, 2020 Share Posted June 23, 2020 (edited) Wait, have you singled out the bad relay? Replace it! I haven't run an oscilloscope on anything since college, so I can't give you specifics on what to see. The fact that you know what pulse width modulation is (although that's a pretty vague term), I'd bet you be successful finding a good page on settings for the scope and what the waveform should look like. From what I remember back in the day, the signal is not PWM, like you'd see in a modified sine wave, but a pulse with a certain width for duration of injector open, period. I.e., more throttle, wider pulse width, more fuel injected. If you post up here a pic of your scope it might jog my memory; some of us can also use the ethernets to help you research whether your waveform looks good, too! Edited June 23, 2020 by gathermewool '15 FB25 Magnatec 0W-20 + FU filter (70,517 miles) RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where Link to comment Share on other sites More sharing options...
bsheaffer Posted June 28, 2020 Author Share Posted June 28, 2020 Well.. I just typed a book that got deleted because four logged me out... but here's the summery.... -don't know what relay, but swapping them did nothing, it doesn't even make sense that any of them would be going crazy inside the cabin. only the starter relay is controlled by the ECU, the IG1, IG2, ACC1, ACC2 are all controlled from the Keyless access CM. It sounds like those main 5... but not sure... the only other cabin relay with ECM control is the Starter Cut. all other is misc stuff like defrosters etc. So that's driving me nuts..... because the only relay that could affect the engine got swaped and still has issues. and if the relay was a cause it would brownout the ECM causing more issues then just one... noticed the 5th gens had a cyl 2 misfire issue after 5 years (same age as my car), been looking at that... -Fearing the worst (Bad ECM) (doesn't make sense) -Prolly have to go to Subaru and pay $800,000.69 to have a diagnosis and part run around. Plan for today, flop & inspect injectors; Flop and inspect spark plugs (99% sure not the issue), Track down Pesky Relay!, Do some o-skill-a-skating. wish me luck! now hopefully this posts and I haven't been logged out and this message deleted on return. or ima rage and you'll get a short short "Relays make no sense, then why is it going crazy, next to check injectors, hunt culprit relay circuit, use o-skill-a-scope." Im copying that sentence in case It failed to post but actually saved it wow! - copying it all, reloading page and trying again... how is it my car that runs like a potato is running better then this four that looks straight out of the year 1625? Link to comment Share on other sites More sharing options...
PATS4LIFE Posted June 28, 2020 Share Posted June 28, 2020 I would check check the inlet valve clearance on that cylinder,most likely cylinder is nearly to zero valve clearance Link to comment Share on other sites More sharing options...
Grnlantern1 Posted June 30, 2020 Share Posted June 30, 2020 Hopefully you have Warranty.. Good Luck and keep us posted. Sent from my SM-G988U using Tapatalk Link to comment Share on other sites More sharing options...
bsheaffer Posted June 30, 2020 Author Share Posted June 30, 2020 Unfortunately no, no warranty, I hit 60 k in November and it turned 5 March 26th. Even though it’s only one, I’m over both 60k & 5 year... it was acting up before that point, only very minor. Where they wouldn’t of done anything anyway. But all we got to was check and flip spark plugs. It was pretty black for 3k miles of uses, even the ones replaced at 63k “were not that bad” after flipping them I would actually idle right with a coupple “normal” hick ups, but still “undrivable” I know I said I’d get to but injector is what I and a coupple friends I consulted feel Is a worthy candidate. Atleast some direction. It has been sitting a lot with all this going on, so maybe extra gummed up. But while gas was free I was running the magical shell premium. Makes me kinda hate it because it’s what I been running as it’s been deteriorating, but im sure it’s just coincidence with sitting. But it was sitting since end of the year for longer periods. Still haven’t looked into what relay. It mocks me in my sleep... Link to comment Share on other sites More sharing options...
gathermewool Posted June 30, 2020 Share Posted June 30, 2020 Sounds like compression and leak down tests are in order. '15 FB25 Magnatec 0W-20 + FU filter (70,517 miles) RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where Link to comment Share on other sites More sharing options...
bsheaffer Posted July 12, 2020 Author Share Posted July 12, 2020 (edited) We currently tearing into to things. Things keep degrading more and more. Cyl 2 (the original problem) is not coming up as often, it has seemingly moved to 1 (where I flip flopped spark plugs, 2 to 1) I think 2 is still messing up but not showing up. It was still acting up after the spark plug flip flop. Now it’s saying random/multiple misfires and cyl 3 I also got a code the other day (P1494) witch appears online to be an EGR issue. Decided to pull that out and it doesn’t look so good... from what I was seeing online it could be a potential problem? I’ll try to include a photo Ima flop injectors, but considering its “spreading” like a certain current disease I’m going with this EGR lead. Any other Ideas? https://ibb.co/TBLXCfr https://ibb.co/wzXDCfH https://ibb.co/QfpQd1v Edited July 12, 2020 by bsheaffer Add other photos Link to comment Share on other sites More sharing options...
gathermewool Posted July 12, 2020 Share Posted July 12, 2020 (edited) Your EGR pics look normal. The code is a circuit issue. Instead of jumping to conclusions, I’d check the wiring harness and connector of issues; if not, reconnect and clear the code. If it comes back then you’ve either got a bad EGR valve (electrically) or something in the upstream wiring is messed up. I had a stuck open EGR solenoid on my previous ‘97 Legacy that never caused these kinds of issues. The only code I ever got was for the EGR system (very generic - took me a long time to trouble-shoot). Our EGR system is much difference, so I’m not sure how to trouble-shoot it beyond what I’ve stated above. My only point is that wouldn’t be convinced that the two are related unless something else is the cause, such as melted wiring along the same harness (e.g., if the #2 cylinder wiring AND EGR wiring were melted or something) / When you say #2 isn’t coming up as often, what do you mean? It’s either still an issue or it isn’t. / Flopping injectors isn’t a bad idea. Edited July 12, 2020 by gathermewool '15 FB25 Magnatec 0W-20 + FU filter (70,517 miles) RSB, Fr. Strut Bar, Tint, STI BBS, LED er'where Link to comment Share on other sites More sharing options...
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