Need some help with my engine misfire problem

[TomsSVX]

we will take a look at it at reading 4 ya

Tom

[svxcuseme]

I went through this ordeal and still have the problem...misses at low RPM. Tom suggested at one point that it could be a leaky injector. I'm leaning towards this as I've replaced/tested everything else...literally EVERYTHING except the injectors/seals.

I have another SVX I'm planning on swapping out the fuel rails to see if this helps....just have'nt made time for it. Besides it's easy to work around it with a manual trans

Good luck. Let us know what you find.

[Cappy]

Here's what I've done so far to try to solve this engine shake problem.
New plugs, new fuel filter, new PCV valve, New Knock Sensor 1, "new" MAS and air filter, sea foamed the vacuum system, cleaned the throttle body, and ran a few cans of injector cleaner thru the system. I've also tested the primary side of all 6 coils and they appear to be OK. I also checked the three coils on the passenger side with a $7 spark tester from Advanced Auto (Help brand), and they appear to have a good strong, steady spark. I need to do the driver's side next, and I need to replace Knock sensor #2, since it's the one throwing a CE (this started about a month AFTER the engine shake).

What the hell else IS THERE? (plenty, I'm sure)

I've decided I need to remove the Intake collector, since my hands are simply too big to reach that knock sensor on the driver's side. So I was thinking of ordering a set of phenolic spacers from Outlaw Eng. Did they finally work out their "green goo" problem?

Thanks,
Cappy

[Earthworm]

Did you check the timing belt to see if it jumped a tooth?

[Beav]

T-belt jumping won't cause a speed/load dependant misfire.

Your description indicates a high(er) load secondary ignition breakdown. I'd guess that you have spark leakage through the spark plug boots. You need to examine them extremely close for streaks - some are lighter, some are darker - that would indicate the leak(s). Think of the boots in the same manner as spark plug wires on other cars.

[Earthworm]

Sorry, didn't realize it was load dependant. Sounds like a spark issue to me as well then. Seen it happen in person.

[Cappy]

Thanks guys,
I'll remove the coils and inspect the boots REAL close inside and out, this weekend & let you know what I see.
Cappy

[Cappy]

Well, now I know why I'm not an auto mechanic. After rechecking the five coils I could get to again & finding nothing, I decided to give the kid a Huebner's one more chance. I'd already replaced the #1 knock sensor, the fuel filter, the PCV valve, a couple of hoses, and checked the vacuum system, run some fuel injector cleaner thru, ran some "sea foam wannabe" stuff from Valvoline thru to clean the valves, checked and cleaned the MAP and TPS, scrubbed the throttle body and butterfly valve, changed the spark plugs, and did a fair amount of cursing, praying, and bleeding. So I tell the kid all this stuff, and the first thing he does is pull the one coil that I didn't look at - you know the one - and guess what? The "copper" tip is black, and there are white streaks inside the boot! So he replaced the coil, and now it runs like a champ! What are the odds of THAT happening? (well, actually, they're 1 in 6.). Beav & Tom were right on the money with this one! (You guys should apply for "Click & Clack's jobs when they retire.) My faith in Huebner's has also been renewed. He also replaced the knock sensor #2 for me (THAT'S where he made his profit - 3 hours labor) and the car no longer throws that CE & now runs GREAT. Now if I can just get rid of this voice in my head that keeps repeating "You're an IDIOT, CAPPY!", I'll be great too.

[svxcuseme]

congrats on finding the fix!

In thes cases, where exactly does the spark leak most often occur. I'm having this issue still. I plan to replace injector o-rings this weekend (this is my last option before throwing my hands int he air and prayer to the subaru gods).

I've gone through all coils and saw no streaks, bad areas on the copper coil contact etc. I even swapped out all coils with know good ones from my spare SVX and no change. I'm pretty sure it's not coil related but would like to know where most of you are seeing the sparK leak, just to triple check.

Do the spark leaks occur at the back of the coil boot, where it attaches to the coil or out the tip of the coil boot, where it attaches to the plug? I know dumb questions but I don't want to assume anything.

Txs!

[Cappy]

Mine was at the plug end.

[Cappy]

OK, after many months of aggravation and expense, the tech at Huebner's replaced a single coil, and that solved 80% of my stumbling problem. But it still was doing it...especially when the AC was on. So I drove up to Akron to visit Budfreak. When he saw what my car was doing, and noticed the new compressor was hesitating as it spun, he suggested checking the AC level. Long story short, it was WAY overcharged. Almost into the "Danger" zone. So much for having a Subaru dealership do AC repair work. Anyhow, he bled some 135 out, destroyed a few ozone critters, and it stopped the compressor hesitation & even really seemed to help the engine stumble. But then he did something WONDERFUL. He gave my car a "sea foam" treatment. Man, I never saw so much smoke come out of a car! I thought he'd blown a head gasket! After it was done, though, the car ran PERFECTLY. I didn't hesitate for two days, and now only on rare occasion does it stumble - again when the AC is on. So this sea foam stuff is like Captain Marvel's magic elixer...it cures what ails ya, if you're an SVX. Oh yea, and my gas mileage went up to 24.5 on this last tank! It was running around 23.
Thanks Budfreak!

[Budfreak]

Anytime my friend. Thanks for coming up and hanging out with us and buying lunch. Glad to hear the car is doing well. We'll have to work on the rest of that stumble when we get a full day to play around with our cars.

[svxcuseme]

Cappy...My occasional stumbling under load at 1800-2000 rpm turned into horrible running once the car got warm..So it made it a lot easier to diagnose. I had more then one coil going bad.

I also had spark leak even though it was not detectable from the boots. Got a feeling you have the same intermittently bad coil situation. Sucks that they are so expensive. Makes troubleshooting a really expensive pain when your measurments are inconclusive.

I replaced the boots with modified, standard spark plug boots and coated the inside of the boot with Silicone grease, per Beav (Great suggestion!). You can see the boots in my locker. Pulled the rubber plugs off a junkyard car...$3 bucks! Cheap fix.

Good luck. Thanks for the info on Seafoam. May try this myself.

[tommy96LSi]

Being a new svx owner (and a young one)... I am not quite sure what exactly is going wrong with her, but i think you guys seemed to have answerred it already. I am getting a CE P0325 (Knock sensor Bank 1 or 1 Sensor) and a p0304 (Cylinder 4 Misfire). I get the same studder under load and the idle is consistent only about half the time. I was hoping that you guys could answer a few questions for me.

Where is cylinder 4 in relation to Knock Sensor Bank 1 (or, is the Knock sensor and misfire directly related)?

Even though the CE indicators are different, does this look like the same problem as Cappy's? I figured that it was electrical, I was just hoping to God that it wasn't transmission.

[Beav]

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