Car is missing like a mofo
 

Ok so My subaru starting missfiring, but I can't figure out why...

I'm not getting any codes.
I've done several tests as well as, unfortunately, listened to a few nasioc members.

Car passed compression test in fair shape considering its got 90k miles,

Did cylinder leak down test and found I have a weak valve on cylinder 4 but couldnt get it to fail the leak down.

Cleaned the maf sensor, which seemed to smoothen out the miss a little, but after driving a while, it seemed to go back to the way it was.

I installed sti pinks and new o rings, thinking that maybe it's a stuck injector, but much to my dismay, the problem worsened.

Its horrible on cold start up. I mean, Horrible!
Doesnt want to start and when it does, it vibrates rediculously. then it sort of
smooths out. but the miss is still there.


I replaced all 4 coil packs, dissasembled, cleaned and used new gaskets on manifolds, both exhaust and intake, new plugs,

Current mods on the car.

Cobb ram air kit.
Perrin Afta- maf
Perrin Turbo Inlet
Css tmic
Forge 100% recirc valve
Helix catted downpipe
New Oem plugs
New Oem coil packs.
Sti pinks
New Exhaust manifold and up pipe to turbo gaskets
New intake manifold gaskets
Im at a loss for words at this point.
Cleaned out pcv lines.

I've taken the car to 2 places, and neither 1 could find the problem.
They both ruled out that its not because of lack of spark.

ummm is ur car tunned for those injectors!

no and I'd rather have the car not missfiring when it gets a tune.

Boost leak test?

Im fairly certain a boost leak wont cause a missfire all the time.

Not being tuned for those injectors is part of your problem. Install the stock injectors or get tuned for them and get a new set of spark plugs. Your car is running rich as hell right now and has most certainly ruined your plugs already.

Did this happen after you did any of these mods or has it been running good and just started doing this?

What plugs are you running? The stock NGK's are best.

Check the turbo inlet pipe where it connects to the turbo. This pipe is famous for ripping and causing a huge preturbo leak.

The car never gave me any problems until a little while ago.


It has new plugs. and in fact they are the stock ngk's.
Already had the inlet off and checked for any cracks and tears.

I noticed before I installed the pinks, that when I had taken the exhaust manifolds off, the valves where almost white.

Unfortunately your best bet is to put the stock injectors back in or get a map that supports the pinks flashed since its compounding the issue.

the injectors will be fine to run and drive on untuned. I have a feeling you have an injector plug messed up. Seems like one of the wires is pulled from the clip. Pull each injector clip an narrow the misfire to one cyl.

another thing that can happen is when you installed the plugs you could have pushed the gap shut on the plug... which would cause a massive misfire as well

Only problem was... it was doing this Before I installed the pinks.

I just noticed my oil pressure gauge is irradic. Im praying its just the sending unit.
But if it weren't the sending unit, what would that mean? would this have anything to do with the random missfire? Is the oil pump shot?

The gap def didnt get pushed shut. otherwise it would be a consistant missfire.


I also noticed that the car has an extended crank, then it starts, but barely.

The car won't have a miss due to oil pressure. These cars have no fail safe for that. When was the last time the tbelt was done? Have you checked your timing marks? What is your CEL status? Also, do have anything that will pull data from the ECU?

compression check time

Timing belt was done at 60k. Cam gear marks were dead on and still are.


As stated in the first post.

engine passed Compression test and cylinder leak down tests.

I have no CEL. Thats whats fustrating me the most.

I have romraider software and the latest Tactrix cable.
Before I installed the pinks, the ecu was holding a lean code. But Now that the pinks are in, I don't know

My problem is posting my logging results.

Ok... so... thats it? All the subaru owners and no one has had or a problem like this?

Have you tried top engine cleaner? Maybe there is some carbon build up? Also have you pulled your plugs since you've changed them? Did you notice any oil build up? Is your engine eating more oil then usual? Have you tried to reset the ecu? How many miles are on your car now?

I'm guessing you found the problem since you haven't come back and told us what was up with your car or asking more questions. :lol:

Turns out that the tensioner must have slipped or somthing strange happened because the passenger side exhaust cam gear was off by 3 teeth... now, shes runin smooth as glass.

But... I still have a small problem. I watch my boost/vac gauge and when I get into boost, I have to give it alot of throttle to get it to build boost.


Leakage somewhere? or it could have somthing to do with my surging tune?

3 teeth?? That is a lot! Valve issue most likely

I'd easily go with you on this one. 1 tooth you can get lucky and your car just run like crap, anything more then that at least from what I've seen is generally bent valve land. That being said anything can happen.

just replaced the plugs again, they were fouled somthin horrible after running pinks with no tune.

So, I threw a fresh set of stock ngk's in.. Car is driving beautifuly again!
but still surging like a mofo