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Plug swap failed to fix miss on my WRX - looking for ideas


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I logged a 'run' at mostly 2k rpm in 4th gear. There's a stoplight in the session. Anyone here familiar with RR logs?

 

I'm wondering also, is there any reasonable way this is related to my
bad Secondary Air valves? That is, they rusted closed some time ago, I
pulled the fuses and relay and killed the 15 or so codes with
RR/ECUFlash.

But, suppose they have moved or have corroded more? Could some kind of
vapor buildup in them and detonate? To my knowledge, no one has reported
a downside to treating the valves as I have, but.....

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They've been known to cause strange issues like this. You can take it off and check under it for giggles. Usually the base can be cleaned and coated with anti-seize or some other anti-corrosive paste.

Might just check and clean it before spending $40 on it.

I'm trying to remember if the turbos have more than one knock sensor though. I think the 6 cyl engines have two.

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Have a jdm 2.0 a'm working on this week has a lefthand turbo failure is over boosting it should be at 7-8 psi and was jumping to 10 -14 psi the feul cutoff is at 8.5 psi so anytime it overboosts the engine shuts of is a real pain to diagnose. Is it posible that its doing somthing like that do you have a boost gauge ? it could be pulling timing if its boosting to high also have seen many knock sensers that do not ground i file the bottom and the block the cleaner the better.

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no mention of a boost problem. I could post the log here if anyone is interested. I don't understand half of it. I think the boost is OK. They seem concerned about the IAM which is one of 3-4 parameters related to timing.

 

I think also you may be right Ivan about the sensor's mount location maybe not grounding well(but the sensors has a 2-wire connector i think?). My car stays outside and, as I've mentioned before' I already had to kill the codes for the secondary air valves and pump due to them rusting closed in 4 years. So. if the knock sensor is prone to corrosion issues, maybe a new one is called for.

 

I'm hoping it won't be too tricky to replace or clean under. I plan to try to at least wire-brush under it. I understand I have to duplicate how the pigtail 'dresses' away from it due to some lumps and bumps on the block around the mount area. i may need to pull the intercooler - never did that before.

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With the age and mileage, it would be uncommon if it had a collapsed valve seat, especially since you say your commute is all city street driving. It's definetly something that I wouldn't see everyday but it can happen. Only way to know is if you check the valve clearance.

 

I know it's not something that's going to be fun by any means, I detest checking valve clearances so I check everything else before I dive in. If I have to get that far, most the time there is something going on with the clearances and it needs a valve job.

 

I can also help walk you through it too. Just let me know.

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Hey tex the 2.0 i was having problems with they had broken the coils installing plugs and had used a high resistance autolite platnum plug the autolite plug was 12 ohms and a v power ngk is 4 ohms it made the spark jump down the side insted of down the plug. Made the car very weird and run poorly and shut down. What plugs did you use ? have had very bad luck with platium or irdium plugs being to high of ohms i like the plian jane ngk vpower with a tight gap it instantly fixed thiss car well and 4 coils. Put a ohm meter on you plugs and see what the ohms are.

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I used the same stock number. Remeber, I changed the plugs to try to fix the problem, it didn't change anything. The coils and the 'snoots' etc. all looked good. No oil.

 

 

did that 2.o set any misfire codes?

 

And the guys ocer at scoobymods that thought I had a knock problem were just confused by my having a 32 bit ECU. The IAM number starts at 1 and not 16. They though I had huge knock and the system was pulling timing. As a coincidence, RockAuto was out of stock so, I canceled the knock sensor order. It wasn't gonna be expensive, but don't really see a reason yet to swap it.

 

this is what the log looks like - all 3rd gear at wide open throttle from 2K to near redline ;

 

 

tailwindrun.jpg

 

 

there are 2 weird cells, Ignition total timing at 3978rpm , and engine load at 4898 . I have no idea if artifacts like that are common, if I was logging too many parameters or if the car missed or ?????  I have another runn I need to look at, just hard to get excited about it. I don't understand half of that stuff or how it inter-relates. Clearly, doesn't look like I need to log the variable valve system anymore. Probably don't need intake air temp or all those mass air flow/manifold numbers either.

Edited by 1 Lucky Texan
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Try a v power plug from a 91 legacy 2.2 bkr6e-11 with about 0.55-0.60 mm gap seems to work best i have no faith in platium plugs or irdium plain is best. I would still meshure the ohms of your plugs and see what it is the v power is about 4 ohms. And i dont know even if subaru knew this it may be very overlooked i think the coil on plug cars need low ohm plugs

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well, I have no idea if it will fix the 'miss', but I discovered I seem to have a crack in the Y pipe under the intercooler. Well, actually, at the elbow to the turbo. Never took the IC off before. There's some kinda foam insulation taped on the part, and there is grime built up ONLY on the elbow, it's clamp, and the foam next to it. None on any other part nearby. I'm thinking it got stressed when I had the dealer do an 'indcution' service and replace the PCV valve back when the car was getting a wheel bearing installed.

 

so, I have a MIshimoto kit coming. I'll probably know in a week or 2 if it helps the problem. I'll try to take pics.

 

Such low miles, seems like the car is not aging well.

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  • 2 weeks later...

OK, I'm about 1/2-2/3 finished with this IC Y pipe swap. I had noticed some grime on the foam insulation wrapper in the area where it attached to the turbo outlet. I ran my hands around and looked all over - couldn't find any other spot so, I figure the dealership cracked it back when the installed the new PCV valve and did the thottlebody cleaning ('induction' service). I decided to
pull the foam wrapper off after i got the Mishimoto pipe on, just to see
what the hole/crack looks like - and of course, the stock pipe looks
OK.



That means, the oil/grime WAS deposited by something nearby. So, either
it was leftover from before the dealership did the PCV valve/induction
service, or there is a problem with the new-ish pcv valve? Another
reason I'm suspicious, last time as well as this time, I poured what
seems to be water out of the crossover piping attached to the IC. maybe,
1/4 to 1/2 teaspoon. It was clear and smells more of oil than coolant.
Dunno if it's normal to have some condensation in there or not. Seems
like, eventually, that's gonna go into the intake right?



I guess, before I reassemble everything, I'd like to see a line drawing
or good pics of where the , I guess, breather hose? goes vs the hose
from the PCV valve (I guess that's the one with the electrical
connection?) Also, off the car and disconnected from the connector,
should the PCV valve be open in both directions?



there are 2 hardlines in front of the turbo outlet down low. Which of
the hoses - PCV vs breather, goes on the rear hardline, which to the
front hardline?

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suppose I said this were a noise, the 'chk' sound, and a surge? I've had this thought for a while, that the 'buck' I feel might be a momentary forward surge and not a backwards 'power loss'. Is that even possible? It's hard to tell.

 

what are the symptoms of BPV/BOV or waste gate problems?

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car warming up this morning, it made the 'chk' noise (uncharacteristically, I had the radio off)so, I decided to listen for a while and watch the rpm needle. It was still warming up and the rpms were at 1500, it made the noise and the needle popped UP slightly.

 

yeah, up

 

so, either i have been feeling a 'surge' instead of a 'drop back' or, some kind of weird coincidence.

 

I have no idea how that could happen.

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OK, the latest was a suggestion on another Forum.

 

i THOUGHT I had eliminated the a/c comp. being an issue when this began. Still not certain, but, today I adjusted the temp to cause the comp to cycle while I watched and listened under the hood. Everything seemed OK ('maybe' there's a slight crank pulley wobble, could be an optical illusion caused by markings on a belt).

 

but, sitting in the driver's seat, I tried to hold the rpms at 1500, where it made the noise that morning as mentioned. Well, I cycled the comp on/off and it seems to be very close to the sound I hear. I might also be feeling it 'buck' a little. So, tomorrow I'll try to cycle the a/c while actually driving at 40 or so in 4th gear.

 

About 4 months/2500 miles ago, I installed new acc belts (Gates). maybe the a/c one is slipping now? I pushed on it and it 'may' be a little loose. It doesn't 'squeal' though. Or maybe my compressor is going bad.

 

This would explain pretty much everything. Even a few days recently when I didn't hear anything. I either had the system off, or the climate control never used the a/c for defrost or cooling. (temps here have been widely variable in recent weeks).

 

I canceled my appt with awdtuning . If I am unable to convince myself it's safe to drive the car after a day or 2 of scr3w1ng around with the a/c comp and its belt, I will probably still need to visit a mechanic.

 

I feel kinda relieved, but kinda stupid.

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