Hey guys just looking for some idea's here. I have an '03 WRX that is reflashed to stage 1 using open ecu. Last weekend I was driving and had the check engine light come on. Noticed that boost was dropping off to about half after 5k rpm. Before that it was fine. Checked the codes and it's a misfire in cylinders 1 and 3. Haven't had a chance to get under the hood and really look at things yet but I should get a chance tonight after work. I tried seaching the forums and came up with nothing. Any idea's what could be causing this? I did have the clutch changed about a month and a half ago at RS Motors in Burnsville. When I got the car back the entire drivetrain felt really loose. Went under there myself and found that the rear tranny mount bolts were finger loose. Also had some exhaust mounts loose that I tightened. Since then I have had what sounds like heat shields chattering from the engine bay during engine braking, but I've been too damn busy to get under there and look at things. My first thought when the check engine light came on were that they forgot something else since it was dropping boost after 5k. The clutch is an Exedy Stage 1 with an ACT light weight fly wheel (not the ~9 lb one, it's the 13.9 lb one). I'm not really sure what it could be but any suggestions from you guys would be greatly appreciated. Hoping to get all this sorted out quickly as I have my first auto cross coming up this weekend... -Jon
the misfire could be the flywheel, BUT it could be a million other things too check the plug on that cyl, move that coil pack to a different cyl see if the misfire code comes back but that cyl, or it could be a burned valve, though not as common on 03s it still happens.
Well these are all things that I'm going to check tonight, BUT it's multiple misfires (cylinders 1 and 3) so I'm thinking something else is going on here...
A super-light flywheel will cause misfires on all cylinders, in many occasions. Also, you will get a differential grind when engine braking. Get used to it or learn how to drive with it. The fact that you have a 13lb flywheel and an ECU flash should relieve some of those issues, though. As far as the "dropping boost", how low are your readings? Is the engine pulling vacuum or are you limited to lower boost? Also, did you do all of these modifications at once?
Do some seafoam into the intake and upper end. My girlfriends 02' WRX had a cyl. 3 misfire that is gone now.
The ECU was reflashed back in February and I haven't had any issues with it since, but the clutch was finished at the end of July. All these issues started 3 days ago (Friday afternoon). The car seems to run fine and pull hard to 5k rpm then the boost gradually drops to just under .05 MPa by the time it hits redline. I'm assuming it's because it's misfiring at those rpm's causing less pressure through the exhaust therefore it can only produce half the boost it regularly does. So you think the grinding/chattering noise when engine braking is a differential grind? That's great, seeing as I engine brake everywhere and it's very loud most of the time. Will that cause any damage to the diffential?
I'm not sure about any damage, but it can be annoying as hell. Try changing your tranny fluid to Uncle Scotty's mix, it actually made a lot of the whine go away for me. Your boost issue sounds like the ECU is dropping into limp mode at the high RPMs. This is where some of my knowledge will get a little light, but I DO know that the ECU runs about 7 lbs of boost pressure when it's running limp mode. I will need to let this one roll over to some of the more fluent owners on here.
I just saw the thread about "Scotty's mix". Definitely think I'm going to try that soon as my 5 speed grinds into 1st a lot too. Hopefully that takes care of that problem, if not, the flywheel has got to go. I bought the 13.9 lb wheel to avoid issues the 9 lb one gives... Not worth the annoyance. But back to the original problem, anyone?
"Around 5k RPM" is torque peak. That is where you are most likely to experience detonation under loaded conditions. Did you recently fill up with gas from a different station? Was the car hot? Had you just been sitting at a red light waiting for traffic? What was the temp outside? As mentioned before, misfires can be caused by any number of issues. However, misfires happening right around torque peak make me think of detonation and other nastiness. A few other questions I have are: When is the last time you changed your plugs/wires? How much blowby are you getting in your intercooler? Do you have a lightened/underdriven crank pulley? That's all for now.
Car wasn't hot, same gas as usual (92 octane). Not sitting in traffic either it was normal driving. It came on when I took off after a stop sign (not accelerating too hard). Temp outside Friday afternoon was probably mid 70's I think. As far as I know the car has the stock crank pulley. I just changed all the plugs, plugs # 1 and 3 (pass. side) had lots of heat damage (very white), and plugs 2 and 4 (driver's side) were much worse, haven't had plugs that bad in any of my cars. Changed them all and I had the battery disconnected the whole time so the check engine light was reset and hasn't come back on yet, but it's still dropping boost past 5k rpm. What could be causing this?
if you changed the plugs then it happened i would go over all your intake piping and make sure everything is connected, no hoses or clamps are loose... again... it could very well be valve issues, try some seafoam if you havent already... re-check the gaps on the plugs (highly unlikely), go over anything you pulled apart and make sure it is all good.... if not get someone who can openecu to pull some logs and look at it... take it ti FS and take some guys for a spin and let them see it in person...
Sorry, when I said I just did the plugs I meant just now, tonight. Before that I never looked at them. I properly gapped them just before I installed them too. I'll see if I can get a hold of a laptop tomorrow to use open ECU (I have the cable, but no longer have a laptop). I will also try some seafoam tomorrow. Any other suggestions for the moment?
It drops to just under .05 MPa by redline. Gradually starts dropping after 5k. Never noticed it before. How much boost should I be hitting? I was under the impression that stage 1 was supposed to up the boost slightly over stock, but mine is still running what it was stock.
depends on what the map is calling for But if the stock td04 turbo, it should begin tapering around there down
Well the CEL hasnt come back yet since I did the plugs, but I could feel it misfiring at idle this morning before the engine warmed up. It was a steady idle but it just felt like it was misfiring. Kinda strange...
Burnt exhaust valves? Mine has been doing this since I bought it. Codes all the way from 1 and 3 misfire...to the whole damn thing 1-4 misfire. Basically throws whatever code it feels like at me when it comes to the P030_'s. Swapped coil packs around, did the plugs, swapped out ecu's 3 times. The only thing that I've heard gets rid of it, or sounded like it anyway, was a thread by a member here(mnstylinwrx?) that had the same issues and discovered he had burnt exhaust valves and I believe he ended up rebuilding the engine. :dunno: Couldn't find the thread I was looking for, but this one came up in the search. Look here>http://www.mnsubaru.com/forums/showthread.php?t=9987&highlight=burnt+exhaust+valves
