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Old 03-05-2020, 08:45 AM   #26
adesso
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Originally Posted by spoolinsti05 View Post
The avcs solenoids?
Correct. Even had beautiful oil pressure. They were the very last thing replaced in all this. It was a huge pain in the ass diagnosing it all.
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Old 03-05-2020, 01:14 PM   #27
Markopolo400
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If you figure this out please post your results.

I have a 2002 bugeye with eeerily similar symptoms. I've been logging on the AP and emailing back and forth with Cobb to try and find a smoking gun. Had to update the firmware on the AP and need to re-log, apparently they have added some new monitors that might help diagnose whats going on with my car.

Have you tried pulling an idle log to see if anything wacky is going on?

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Old 03-05-2020, 01:33 PM   #28
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Originally Posted by adesso View Post
Correct. Even had beautiful oil pressure. They were the very last thing replaced in all this. It was a huge pain in the ass diagnosing it all.
You didn't notice a variation in avcs operation? Usually when they go bad you'll get more advance on one cylinder vs the other.
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Old 03-05-2020, 01:34 PM   #29
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Originally Posted by Markopolo400 View Post
If you figure this out please post your results.

I have a 2002 bugeye with eeerily similar symptoms. I've been logging on the AP and emailing back and forth with Cobb to try and find a smoking gun. Had to update the firmware on the AP and need to re-log, apparently they have added some new monitors that might help diagnose whats going on with my car.

Have you tried pulling an idle log to see if anything wacky is going on?
Check fuel pressure and avcs function. I can see an issue if the solenoid is jammed open causing avcs to operate at idle.
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Old 03-05-2020, 01:41 PM   #30
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You didn't notice a variation in avcs operation? Usually when they go bad you'll get more advance on one cylinder vs the other.
I didn't have a way to monitor it before I got my V3 (I was still using a V1 when all of this started)... and once I did, I saw the variation between the two heads. Pulled the solenoids out, bench tested them and they were both within factory specs, but different from each other. Ordered new solenoids, bench tested both before installing and they were exactly the same as each other and installed them. Haven't had a issue since.
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Old 03-05-2020, 02:44 PM   #31
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I didn't have a way to monitor it before I got my V3 (I was still using a V1 when all of this started)... and once I did, I saw the variation between the two heads. Pulled the solenoids out, bench tested them and they were both within factory specs, but different from each other. Ordered new solenoids, bench tested both before installing and they were exactly the same as each other and installed them. Haven't had a issue since.
When you say factory spec can you be more specific about the test you ran.
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Old 03-05-2020, 02:58 PM   #32
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When you say factory spec can you be more specific about the test you ran.
Putting 12 volts to it to test that they were actuating and also checking resistance with a multimeter. Resistance is supposed to measure between 6 and 12 ohms. Mine were both within spec but different from each other. The new ones measured exactly the same amount of resistance... I want to say they both measured to be 8.1 ohms.
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Old 03-05-2020, 04:10 PM   #33
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Putting 12 volts to it to test that they were actuating and also checking resistance with a multimeter. Resistance is supposed to measure between 6 and 12 ohms. Mine were both within spec but different from each other. The new ones measured exactly the same amount of resistance... I want to say they both measured to be 8.1 ohms.
A sensor while heated will read a different ohm also. So it needs to also be at temp that the manual rates it to be tested.
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Old 03-05-2020, 07:33 PM   #34
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A sensor while heated will read a different ohm also. So it needs to also be at temp that the manual rates it to be tested.
I'm fully aware that heat will affect resistance. I'm not at all sure what you're getting at with all the questions to me and I'm done cluttering this guy's thread. I was merely trying to offer a suggestion for him to pursue since his problem was so similar to mine and many others on here. There a plenty of threads addressing the problems, diagnostics and solutions involving the OCV's on here and other Subaru forums. I'm sure you're more than capable to look them up and see for yourself.

OP, sorry for the clutter and I wish you luck.
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Old 03-05-2020, 11:09 PM   #35
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I'm done cluttering this guy's thread. I was merely trying to offer a suggestion for him to pursue since his problem was so similar to mine and many others on here.
Please keep 'cluttering'.

I've been taking a very hard look at the AVCS solenoids or even that whole variable valve system. I can envision a situation where the engine is stopped 'hot'. The valve adjustment does not immediately return to its starting point, but does complete this return over many minutes. It could be something mechanical, but a funky AVCS solenoid is more likely.

I described my 'problem' in the first post. One additional manifestation occurs as follows: I'm on the highway running hot. I come off an exit and suddenly find myself in bumper-to-bumper stand-still traffic.

Sometimes this works out okay, but sometimes the really-bad-idle-demon appears (with his spurs on). The 'fix' that I've used is to slip the car into neutral and increase the engine speed to ~1500-2000rpm. After a minute or so, the demon goes back under his rock.

Adesso: which replacement AVCS solenoid(s) did you use? OEM? I looked on Rockauto and did not recognize any of the brands they were selling.
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Old 03-05-2020, 11:25 PM   #36
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I'm fully aware that heat will affect resistance. I'm not at all sure what you're getting at with all the questions to me and I'm done cluttering this guy's thread. I was merely trying to offer a suggestion for him to pursue since his problem was so similar to mine and many others on here. There a plenty of threads addressing the problems, diagnostics and solutions involving the OCV's on here and other Subaru forums. I'm sure you're more than capable to look them up and see for yourself.

OP, sorry for the clutter and I wish you luck.
What I was getting at is I can't see a solenoid testing good in all acquired test conditions and being bad. But I suppose. Anything can happen. As well as the avcs gear "sticking" causing the solenoid to jam up. Figured you'd get a code unless a tuner disabled it.

Let's keep this civil LoL.
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Old 03-05-2020, 11:32 PM   #37
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Originally Posted by davefedex5358 View Post
Please keep 'cluttering'.

I've been taking a very hard look at the AVCS solenoids or even that whole variable valve system. I can envision a situation where the engine is stopped 'hot'. The valve adjustment does not immediately return to its starting point, but does complete this return over many minutes. It could be something mechanical, but a funky AVCS solenoid is more likely.

I described my 'problem' in the first post. One additional manifestation occurs as follows: I'm on the highway running hot. I come off an exit and suddenly find myself in bumper-to-bumper stand-still traffic.

Sometimes this works out okay, but sometimes the really-bad-idle-demon appears (with his spurs on). The 'fix' that I've used is to slip the car into neutral and increase the engine speed to ~1500-2000rpm. After a minute or so, the demon goes back under his rock.

Adesso: which replacement AVCS solenoid(s) did you use? OEM? I looked on Rockauto and did not recognize any of the brands they were selling.
I reviewed you original post didn't see you had this issue (in traffic). Hmm. If you want to try the solenoids I'd get some oem ones. Have you been able to check the fuel pressure? Cheaper then spending money and you can rule out that as an issue.
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Old 03-06-2020, 12:03 AM   #38
adesso
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Originally Posted by davefedex5358 View Post
Please keep 'cluttering'.

I've been taking a very hard look at the AVCS solenoids or even that whole variable valve system. I can envision a situation where the engine is stopped 'hot'. The valve adjustment does not immediately return to its starting point, but does complete this return over many minutes. It could be something mechanical, but a funky AVCS solenoid is more likely.

I described my 'problem' in the first post. One additional manifestation occurs as follows: I'm on the highway running hot. I come off an exit and suddenly find myself in bumper-to-bumper stand-still traffic.

Sometimes this works out okay, but sometimes the really-bad-idle-demon appears (with his spurs on). The 'fix' that I've used is to slip the car into neutral and increase the engine speed to ~1500-2000rpm. After a minute or so, the demon goes back under his rock.

Adesso: which replacement AVCS solenoid(s) did you use? OEM? I looked on Rockauto and did not recognize any of the brands they were selling.
So, your issues sound almost identical to what I had going on. I'll describe my issues and what I did...

My problem was that I had a slight misfire at idle. I threw codes for a misfire on cyl 4. Misfire would go away as soon as any load was put on the engine. But once the engine was warmed up, the car ran beautifully. I'd drive it some where, shut it down and when I started it back up, it wouldn't want to idle. This could be resolved by giving it a little gas and it would straighten out. This went on for a while and I started digging into it. Replaced plugs, swapped coils, replaced coils, replaced for, smoke test, compression and leak down test, scoped cylinders, replaced fuel pump, pulled injectors and sent them out to be cleaned and flow tested, cleaned MAF, replaced O2 sensor... Even had a few shops look at it and I got all sorts of "answers..." Broken ring lands, cracked ringlands, tight valve, etc... It was frustrating to say the least. After everything was all said and done, I had resigned myself to replacing/upgrading my entire fuel system because everything in my being said it was fuel related as well as a few tuners telling my ancient Power Enterprise injectors suck and were probably the culprit. So, I spent a crap ton of money and replaced EVERYTHING fuel related. Got a new AP, new tune and everything was honkey dory... Or so I thought. Cranked it up, no misfire... Yay! Got it fully warm and then this misfire reappeared. FML. At this point, I figured I was looking at a rebuild... A friend of mine told me to check my avcs solenoids... Wtf... Really? So, I did. I pulled them, cleaned them, check for proper movement and bench tested their resistance. Everything was within spec. However, after a lot of searching on those stupid things, I found out that they are super finicky. I'd already spent a ton of money replacing everything, so what's a couple of new solenoids... I bought OEM ones and out them in... Haven't had one single issue since.

I spent nearly 2 years trying to track this issue down and a rediculous amount of money. The positive thing in all of this is that my engine is still healthy, I've brought my fuel system into the 20th century with room to grow and the car runs better than it ever has.

Your hot idle issue, the drivability that you describe are dead ringers for what I had going on. The misfire issue I had started on cyl 4, but right before I replaced everything, the misfire would register randomly on all cylinders. Again... Once any load was out on the engine, it would straighten out and be fine. It only occurred at idle at hot starts.

I really hope that helps. Let me know if you have any other questions, and I'll try and answer them as best I can.
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Old 03-06-2020, 11:12 PM   #39
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So, your issues sound almost identical to what I had going on. I'll describe my issues and what I did...<snip>
This really helped. I was originally focusing on the crank and cam position sensors - they seem to be a popular failure point on Subarus. I've got the parts on hand to do a replacement.

But now I think I'll wait and change the AVCS solenoids at the same time (the parts should be here next week). The issues are all in the same areas of the engine. So, stay tuned.

Again, thanks. For the first time in this puzzle, I think I'm seeing a light at the end of the tunnel (probably an on-coming STi with one headlight out :-)
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Old 03-07-2020, 12:20 AM   #40
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I would think you'd have a avcs stuck in operation showing positive advance at idle if ot was solenoid
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Old 03-07-2020, 01:11 PM   #41
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I would think you'd have a avcs stuck in operation showing positive advance at idle if ot was solenoid
That may very well be the case. I ran a few errands this morning and paid particular attention to the idle... idling hot, idling cold, etc. Honestly, the engine idle leaves a bit to be desired under every condition. And, this is not a 'learning issue'.

I can imagine a 'stuck' AVCS solenoid as culprit. Once off of idle, the car is running great. So, stay tuned.
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Old 03-14-2020, 02:43 PM   #42
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Any luck with it?
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Old 03-19-2020, 09:15 AM   #43
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I wonder if you have an issue with the ground wire in the engine harness like mentioned in another thread. I'm pretty sure you have that same engine harness in the FXT they say there's a TSB for it. Might be worth looking into!
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Old 11-16-2020, 02:44 PM   #44
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This problem (rough idle, P0301 codes, etc.) has been grinding along for more than a year. Over the weekend, I installed two new Oil Control Solenoids (for the variable valve timing) and suddenly, the problem is gone! The idle smoothed out. The P030n code(s) cleared and did not come back. I replaced both valves although the problem were predominately related to Bank 1 (passenger side).

These solenoids are accessible without disassembling the whole engine - it's tedious to reach them, but it is doable. It helps to remove the intake air box (passenger side, bank 1) and the battery (driver side, bank 2).

The part for my vehicle 10921AA140 - it should fit most Subaru ~2009 onwards. Earlier Subaru vehicles also use these valves, probably with part number 10921AA080. These parts are not interchangeable - they are physically different in size - so be sure to get the one that fits your vehicle. I used genuine Subaru parts via Amazon although there are a slug of aftermarket valves available.

This problem has been a royal headache over the past year or so and it now appears to be gone!
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