vehicle: 2000 Forester, 2.0L WRX motor swap (currently at 50k mi). Spark plugs have less than 2k mi on them and were installed before a tune, so I don't think they could be a culprit. Car has been in the shop a bit since I've owned it (4 mos. or so) but not for engine or electrical problems. 2 days after I picked it up last week I noticed what felt like clutch slip in 5th when boost comes on. Yesterday all of a sudden I get heavy misfires, engine running rough, down on power, CEL flashing. CYL 4 misfire. Get home and it shows CYL 3&4 misfire. Swapped in a new fuel filter, new PCV valve (old was was sticking just a little), cleaned the throttle body which had a good bit of carbon buildup on the bottom, and dumped a bottle of fuel system cleaner into the gas tank. Today there is no improvement, and now I get a CYL 4&1 misfire. Its also showed the PFFF and PFFE codes. Any ideas where to go from here? My next plan was to try a seafoam treatment. I threw on silicone intercooler hoses while I was in there (and was defeated by that PIA bypass valve hose clamp). I've got an accessport so I can datalog if necessary but don't really know what to look for. I'd bring it back to the shop if it wasn't such a PIA to get the car over there. In the meantime I'm driving the car to work in the fuel system cleaner, but am staying out of boost. I do have another car I can drive if necessary if I'm better off not driving this one. Oh, and the exhaust is catless.
I'm pretty confident the plugs are in right, Brandon installed them. And since he had to pull the motor up a bit to get to them, thats not something I can check myself. Also they were installed just before the tune at Topspeed, and I'd imagine if any gaps were off significantly, Doug would notice something was "off" while tuning. The car made 244whp/256wtq on 15psi, so it was running strong(stg2, catless, AP). Clutch was slipping under higher boost, which was the only comment I received regarding the tune.
Oops, fixed it. 244/256 to be exact. If a coilpack was to blame, wouldn't it just misfire on the cylinder that had the bad coilpack? There has got to be almost no chance that #4,3,&1 coilpacks went out at the same time. There's definately been a trend of #4misfire always showing up first, and with more driving the other's pop up. Though still haven't seen a #2 misfire yet.
Oops!! OK so since I had MAF cleaner and seafoam in the garage, here's tonight's update: I cleaned the maf sensor, even though it looked spotless anyways. Codes cleared, test drive showed a mild improvement, though misfires on 4&1 popped back up. Seafoam into the boost guage port off the bypass valve, and here's where I messed up: Got down to just over half the bottle then dunked in the hose, but the car didn't stall. After a moment I pulled the hose out and found the can about empty! I immediately turned off the car, let it sit for 5 min then started the smokescreen. The car kept wanting to stall at first then CEL for misfire on 1-4 popped up. Pulled out for a test drive and still had some misfiring (but less now) and eventually pulled over to reset the ecu. The rest of the drive home was 99% smooth, until I got about 1/4 mile form the house and it started misfiring again as before, on cyl#4. What additional problems might I expect from putting in way too much seafoam? Anything else worth checking/doing not involving removal of the coilpacks?
Stock flywheel. Yes I know I need to take it to a mechanic, and it would already be there if there was a good scooby mechanic near gainesville that I can afford. This is why I'm trying to rule out as many things as possible that I have the time and ability to perform. This morning in addition to the misfire codes its throwing a faulty EGT sensor code. Not sure if this could be related to the misfires or if its a result of the seafoam. The only other thing I can think of at this point (that I can quickly perform) would be the front 02 sensor...anyone think this possibly be a culprit? Otherwise I probably need to stop driving it until I can get it to the shop. I wish the coils/spark plugs weren't such a PIA on this car to get to so I could check compression in the meatime.
no one lives in Gainesville... PM JWX. I think he still lives up that way and has worked for SoG in the past.
Good info, I did not know JWX was a scooby mechanic. Mike from Killshot took a peak inside my ECU with his laptop and found some very significant air/fuel corrections which could be caused from an intake leak, but he definately couldn't rule out any internal issues. So I'm crossing my fingers and hoping maybe its just a crack in the turbo inlet pipe I can't see. He also showed me where the MAF sensor was, since apparently I cleaned the intake temp sensor. Giving that a good dousing of the MAF cleaner still had no effect. Thanks again Mike!! It'll be in the shop next week so I'll post up the result.
Got the car back today. It turns out the problem was the coil packs. Since it was missing on all but cyl2 they went ahead and swapped 'em all out. The hour drive back home was great. No misfires, no CEL, nice smooth power. Thanks AllPro!
Yea its very strange. 4 was missing constantly, and the other two were intermittant. Coil-on-plug ignition definately hits the wallet hard when it misbehaves!
Yea I definately suspected it, but it just wasn't something I could check since the motor has to be pulled a bit for clearance. Not something I have time for or would be comfortable doing without experienced help.
Just thought of something....could poor grounding cause the ignition coils to be more susceptible to damage? I'd hate to spend money on something not necessary but I wonder if a grounding kit could prevent more uncommon problems from creeping up.
I'm not convinced that adding grounding kit will have any impact on your coil packs. But I am glad to hear the car is running well once more. Congrats!
it will if he has a shitty grounding setup to begin with, as a matter of fact that should have been the first thing checked if multiple coil failures.
I actually checked a few of the stock grounds before the coilpack issue and they seemed to be OK. I know the grounding mod can be DIY, I did a home depot grounding mod myself on the WRX I had. I just don't want to do it if its not necessary...IIRC even the home depot method ends up costing only slightly less then the ebay ground kits.
I would guess something was amiss if 3 went out at once. Maybe they were all old to start with or something....but definitely seems odd. Makes you wonder how much longer the 4th has!