K, so I'm driving up 35W last night and after about 45 min I get a kind of clunk from the engine bay followed by a change in the engine note & tone (lower & softer) - RPM's started slowly dropping and I had no power - tapping the throttle did nothing. So I downshift to 4th and it goes away. :ugh: On the way home the exact same thing happened, except I didn't downshift and continued tapping the throttle. After about 5 seconds it just went away. When I got home I pulled the codes and got the normal P1596 for the missing 4EAT but also had the P1507 for the idle air control valve. I can't be absolutely certain that the code was thrown when the car bogged, but I did reset the ECU on Friday, so there wasn't much time for it to pop up anywhere else and I've never seen that code before on this car. This morning, my idle was stuck at 2k+ RPM. Would not go away despite shutting the car off and restarting several times. However, it did not throw the P1507 code again. I've been having strange idle issues since swapping my tranny but wrote it off to the ECU since people said it idles high at first after a reset and I never had the slightest hint of any idle problems before the tranny swap. Normally, after a reset I get a 2k RPM idle for about 5 starts and stops, then it goes back down to like 600-750 range. However, since the swap it randomly decides to idle at 1500 RPM sometimes. The 2k this morning was abnormally high even with the random wandering. I think my first step should be to inspect and possibly clean the IACV and maybe continuity check pair of wires going to it (looking for some continuity across a solenoid coil I assume - if all pairs are open my IACV would be fried, right?). Is that what I should be doing? It sounds like most people with sticking or shot IACV's have much more severe driveability problems than what I'm experiencing, though. Also, my neutral safety switch is still shorted, so the car thinks it's in neutral all the time. What effect would this have? Would it being trying to "operate" the IACV all the time? (sorry, don't really know how this part of the car works, someone enlighten me)
It was weird - they definitely went together. Clunk than bog. One event. Then to find the IACV code and then this morning the abnormally high idle. There has been mild but strange wandering on the idle since the swap. A lot of times it idles fine, then boom 1500 RPM out of the blue (sometimes at startup sometimes random I come to a stop and now it's idling high). Also, on occasion at startup it drops really low and that seems to jar the ECU into raising it to 1500 RPM. The 1500 RPM idle often goes away if I just turn the car off and restart it. I contributed that to the ECU acting weird expecting an auto tranny. People say it's adjusting timing expecting a load to be present from the torque converter. Maybe all that was the IACV coincidentally getting jammed up at the same time as the swap? Could a failing/clogged IACV cause a bog like that at highway speeds, though (remebering that my NSS is shorted so the car's kind of always in neutral)?
I would check for vacuum leak first. Have you tried pulling the IACV and resetting it. I think you have to extend the rod out then install it back in. Typically the IACV control the extra air coming into the engine. It shouldn't restrict your throttle or bog while stepping on the throttle. I would think the bog would be fuel related or TPS gone bad and it thinks you're on decel.
I'll take a look at the hoses, but I didn't notice anything that had come loose when i looked this morning. Plus, it actually was idling okay last night after the clunk/bog - it was this morning that the 2k idle started and wouldn't go away. I'll drive it again at lunch and see if it's still there, maybe take another look under the hood at the hoses and stuff. The bog was weird - it sounded quite different from normal engine operation, not like just letting off the throttle - the whole sound of the running engine changed. It wasn't like, "Hmm, no power" it was more like, "what the cr*p, something's really wrong." But then it just went away. Could a fubar'd IACV have dropped some coolant into the intake? I would think that would only happen if the gasket was shot and then it would be happening more regularly, I'd think. I don't think the IACV would've gotten opened when the head gasket was done, but if it was opened I know that no new IACV gasket went in.
I doubt that you would've taken the IAC off the intake when doing the head gaskets. I would check for the hoses/wiring connections for the IAC. It is possible that it's broken, or that the motor stuck and broke the pintle inside the valve/recess.
^ yeah, having looked at it closer over lunch I see where it is and yeah, wouldn't have come off during HG. Plus, most of my initial fears appear to be moot given the difference between the WRX IACV that has info everywhere and the older NA IACV on my car that much less info is available on - like, it doesn't appear that there's any coolant going through/near my IACV whereas there definitely is on the WRX. Home now, so I'm actually walking out the door with a screwdriver in my hand to pull that SOB IACV off and take a looksee. Any bets it's as clean as the rest of my car? Something inside me says it won't be that simple. Oh - and there's slack in the throttle cables and at first and second glances I see nothing that would indicate a significant vacuum leak - despite being a complete noob, I think that a vacuum leak would cause a much more sporadic and jumpy issue - this is just straight 2k idle. But - I really don't know anything.
Alright, so the IACV appears to be fairly well coated in a fine black oily grime. I couldn't guess if that would be enough to mess with its operation. Guess I'll clean it and see. Noticed what appears to be a crack in a hose, though - but it doesn't look very bad. Can someone tell me what that thing is exactly? I don't even know if it's under vacuum or not.
So, holding the IACV with the shaft thing facing me I can turn it about 15* clockwise and if I left go it returns itself to its original position. It takes very little effort to turn the shaft with my fingers and the movement is very smooth. Again - I don't really know anything - but that doesn't seem like a clogged/stuck IACV to me. Maybe the operating force of the motor is much, much smaller than what I'm applying with my finger, though?
that hose is a fuel line, and its fine. clean the IAC valve off really good, the spinning is normal, clean and re- install, clear the code and try it again.
just finished cleaning - going to look for wd40 for the o-ring then I'm putting er back in. Oh, and the code actually never came back after I reset it last night (after the clunk/bog - and it was idling as high then, though it was like 1500). So, despite the 2-2.5k idle all day, no P1507 code. That's why I have a sinking feeling it won't be this simple. I'll know in 10 min though!
and ....... that did nothing. same high idle - 2k+ won't go away. No code. Anyone else got any ideas?
So - I reset the ECU after cleaning the IACV didn't help. It still idled high, but this morning was about my 5th start and stop after the reset (did like 4 last night), and the high idle went away - just when I would expect after a reset. So, it would seem that whatever happened with the clunk/bog (and it would be nice to shed some light on wtf happened there) shocked the ecu into idling high. Resetting it fixed that, but then of course I had to drive the normal post-ecu high idle away first to know. This much futzing with just a swapped tranny. Do you motor swappers go through like 4 times this much cel crap??? It's frustrating, but as long as nothing serious is broken in the end I guess it all ends okay and results in a learning experience. Hmph. Now, wtf was that clunk/bog? And I notice I get a pretty significant chatter from the front area of the tranny in neutral that goes away if I push in the clutch. Wondering if a bolt came loose in there or something At least I know my IACV is nice and clean!!
You know - I tried 2 different ones - one a JDM with an factory P0420 delete reflash. They both exhibited the same high idle issue. I think I need to disconnect more stuff and futz around. For example, the TCU's still hooked up cause I'm *pretty* sure ABS will stop working when I disconnect it and I'd rather ride it out this way with ABS through the winter than get myself stuck without it screwing around. (yes I can stop on slick roads without abs, but not as fast as with abs, I don't think). I'm thinking if the TCU is completely unplugged and I go with a MT ECU or if the TCU is totally unplugged and I ground the AT/MT id pin and the AT diagnosis pin on the AT ECU I may be alright - but I just gotta try it out.
Yes, we motor swappers go through a ton of troubles too. Mostly fixing leaky hoses and crappy subaru oem spring clamps though, no CELs yet. Turbo EJ engines have a stupid amount of coolant hoses, all of which can leak. That bog I've never experienced before when I was NA, I did have a knock sensor go bad and the car would rev but give absolutely no power the more throttle you gave it, and it sounded like a whimpy version of its normal self. Threw a code, replaced the sensor, problem solved. I was thinking the chatter problem could be the throwout bearing, but that usually makes noise when you depress the clutch, not the other way around like what you've got. Pilot bearing in the flywheel maybe?
I totally agree. I know on the newer cars, the tcu and ecu talk to each other. If the tcu thinks you are in neutral but the ecu is trying to control a driving car, I think you are going to see a bunch of weird things pop up. I know that if I am going down the freeway and I dump my car into neutral, the rpms stay up a bit (maybe 1k or a little higher), and some of that is to reduce the shock of dumping the car back into drive. So remember, once computer things that you are driving while in neutral, and the other is trying to control a motor while the tranny is driving in neutral. Russ
Yeah, Russ - I was kinda thinking along the same lines. I just don't really know on my older car exactly how much the ECU changes how it runs the engine based on what it gets from the TCU. Plus, I tried 2 MT ECU's and that alone didn't fix my swap issues. My FSM's only show one wire going to the ABS electronics from the TCU (don't recall what it was labeled for off hand). I know ABS works if I'm in neutral, but a lot of people say unplugging the TCU makes ABS stop working in these older cars. If it's one wire it can't be that hard to spoof. I don't think the TCU is outputting any kind of PWM signals or anything fancy - most complicated it probably gets is generating the VSS pulse from the 2 speed sensors that the 4 EAT uses. Kinda an interesting circuit there. The TCU gets signals from the 2 speed sensors and then itself generates the same signal that the VSS for the MT directly generates - FSM wiring diagrams show that signal going straight to the ECU & speedo guage. There's also no signals from the TCU to the ECU to indicate which exact gear the tranny is in. Then, I have to wonder if having the TCU hooked up is preventing me from forcing the ECU into "manual mode" - which seems possible from everything I've read so far. That, and I can't imagine what else would cause a known MT ECU (Cubby's) to act the same as my AT ECU, as far as the idle goes. It seems too that vehicle speed is taken into account by the ECU for various behaviors - like not running radiator fans at speed, for example. So not having a VSS is probably in the mix too. And then yet all of that is almost certainly not related whatsoever to that crazy clunk/bog thing I experienced. That seems to have jarred the ECU into idling high until a reset. I would've reset right away - but I knew I'd still have to wait a day or two for my "normal" high idle learn-down before knowing if that's what fixed it. So I figured I'd check the IACV first since it's so incredibly simple to check and clean. Almost quicker than resetting the ECU! I really just need to take my driver's side dash apart and re-organize a bunch of wiring and add in my proper NSS circuit (got a schematic figured with a couple relays to use the reverse and neutral switches on the MT to properly indicate to my AT ECU when I'm in neutral and not). Get that TCU totally out of there. EDIT: Yeah, the clattering too. Very noticeable when it was idling high, only hear it barely & occasionally with the right idle. My first thought once I realized it wasn't actually my hood rubbing my strut tower bar (like I thought at first) was that a pressure plate or flywheel bolt may be coming loose. Bearings both seemed good, though we did use wire to tie the throwout bearing to the fork instead of the clips (cause we didn't have any and Ej22TIM said they were junk anyway). I doubt that wire would be failing - we used a couple twisted copper strands and wrapped it up pretty good. Then again, maybe there's a little play in it and it's wiggling or something and causing the noise - seems like a stretch, though. Oh well - next time I pull the tranny from the motor a lightweight flywheel is going in, so I almost welcome a loose bolt that needs tightening.
BTW - Cubby, I'm still totally up for taking one of those ECU's off your hands. I will be doing an i-Speed reflash by spring and I will want a spare to send in so I can keep driving.
So I had another bog incident. I was cruising down the highway for like 45 minutes at 2500-3000 RPM in 5th. Then I got the bog, but it didn't go away. After several seconds I pushed in the clutch. The RPM's dropped and started bouncing between 1000 and 1500 RPM's. I couldn't get any power in any gear. So I pulled over and shut off the car for a few minutes. Checked the codes - P1507, P0507, P0301, P0302. After a few minutes it started right back up. Had my normal high (2k) idle that I get after a ECU reset or clear. Got another 20 min down the road and it did it again. Pulled over and shut it off for a few minutes. No codes. Stopped at a gas station and threw a bottle of Heet in (someone suggested freezing fuel as a possibility). Another 10-15 minutes down the road it did it again. I killed the car while rolling and restarted it after a couple seconds. Fired back up and got me the last 20 minutes home. Still no more codes. Still idling high, probably still from the ECU clear - should go away by tomorrow. Any ideas? This is too weird. I'm thinking maybe having my NSS switch shorted is screwing with my ECU. Maybe frozen gas. Maybe water temp sensor for the ECU (cause I occasionally get a slightly high little bit hunting idle?). Known issues seem to confound diagnosing unknown issues. I never know what could be related to what. Erg.
01 RS. MAP, no MAF. Cleaned the IACV. Also, forgot to mention, a minute or so before the first bog last night got the flashing check engine light - which obviously was the P030x codes, and the bog didn't happen until like a minute later.
lol, no prob. Really sucks that this car is being unreliable on longer trips right now. Never had the faintest glimmer of problems like this before doing the tranny swap, but I just can't see how the two could be related, other than not having problems before and having problems after. Anyone got any ideas what could be causing bogging after driving in 5th for like 40 minutes at 3k RPM but never any other time (and I mean never)? Something that could be getting worse each time? Could anything like crankshaft position sensor or O2 sensor or something do that? It just kind of feels like a flaked out electrical thing, rather than a mechanical thing - too sporadic and on/off in nature.
Different IACV design on my car and later model WRX's. Not sure if its an NA vs turbo difference or just a later model year change. Mine is a simple o-ring that can be reused. I lubed it up and it felt fine when I installed it - didn't feel any binding or anything. I don't think a leaky IACV gasket would cause such a serious bog - I mean, I could not accelerate the car at all - dropped into 2nd at like 4500 RPM and no throttle position made any difference.
It threw the P1507, P0507, P0301, and P0302 the first time it bogged last night, but not again, despite doing the same bogging like 3 more times. I got the flashing check engine light a minute or less before the bog happened - I assume that'w when the two misfire codes threw, but there were no driveability problems then. That confuses me? The only other time it threw codes it was P1507 only and it was when I started this thread. Having reviewed my records I would guess that I'm due for a fuel filter, at least.
not that many. Did the coil pack not quite a year ago right there in Mtka Morrie's bay. Did wires & plugs at the same time. Did plugs again at the end of summer for good measure after Seafoaming them. First time I've ever had the flashing cel with this car.
I had a similar issue with bogging, cant remember what the code it threw was but I ended up swapping out my knock sensor and that fixed everything. I have a 98 Impreza Outback Sport Wagon.
AWDImprezaL - this is the specific symptom I was looking at when considering swapping in a new water temp sensor. It's damned confusing cause I think I'm up to about 3 different idling issues now. :ugh: As for front AF sensor - I have had the exhaust out a couple times, and while trying to be gentle with that sensor (hear they're sensitive to physical shock), I did kind of drop the header & cat section once but it caught on the not yet disconnected AF sensor wire. Another time it took a bit of a bang onto the ground, too. I guess I haven't considered that more seriously because I assumed if the AF sensor was faulty I'd have a CEL that specifically indicated a problem with it or I'd have more constant problems, instead of just after 40+ min at 3000 RPM. Thoughts? Could an AF sensor only get weird once and a while like that - maybe after it gets really good and hot? I know that last long trip it bogged, but went away (when I started this thread), and since then I've banged that sensor on the ground when I did my suspension, and now it's worse. Thoughts?
I have a used O2 sensor you can splice the wires into your harness and try if you want. I know it was working when I took it out.
If its not the correct one for the car its not gonna work, It will need to be a front A/F sensor for the same vehicle, on newer vehicles like this the rear 02 and the front arent the same.
Not to scare you, but that misfire code is kind of a big deal, do a compression test on that cyl, Ive seen SOHCs start to drop exhaust valve guides and get misfire codes.
Know off-hand if Morrie's does it and for how much? Or any other suggestion on how/where to do a comp test? The other thing to consider is that the headgaskets got done within 50 miles of completing the tranny swap, so the problems didn't appear until after the swap & the HG job. Could something have potentially gotten damaged by improperly doing the headgasket job? (not trying to point fingers or place blame on the person who helped me with that - just want my car to run right again) Also, it was P0301 & P0302 - so that's cyl #1 & 2, right? Aren't those on opposite sides of the engine? If it was something like exhaust valve guides, wouldn't that likely be one cylinder or one side of the engine and have to be a really big coincidence for cyl's 1 & 2? Still makes me wonder - this is the exact pattern that used to pop a P0420, which is too little difference between the front AF sensor and the rear O2 sensor - usually indicating cats not operating properly - but could that have been a pre-indicator of a failing AF sensor? I only wonder cause I simply never get that P0420 anymore - and I used to get that fairly often. In fact, I bought a scan tool because running to Checkers to reset the code so often was getting annoying - and now nothing. Not a single P0420 since the swap.
Ide start with getting some dielectric grease and goobing up your connections on plug wires, both @ the plugs and @ the coil. As for the comp testing, I have no idea what we would charge, on your engine its not that hard of a job. But of course you would need the tool itself.
I did goob the connections up pretty good with dielectric when I installed them last, but it can't hurt to check. Also, suppose a comp test wouldn't hurt. Besides, we're looking at a 2.5 Legacy GT for the GF and I'd like to get that comp tested for peace of mind.
So I made the drive home today. 100 miles at 70-80mph (3000-3500 RPM). It bogged exactly 40 minutes into the drive. Downshifted to 4th right away and it disappeared. That happened 3 more times and downshifting worked each time. None of the bogs were very bad. It was warmer on the way back. Maybe its something that is worse when its colder.
I would throw in a knock sensor, I may have one you can borrow if it works on your car. also, ive got a compression tester if you want to come over and check it.
:wavey: If the knock sensor is reporting knock then the ECU pulls timing or something, right? If it does that, wouldn't it set a specific CEL?