Cylinder misfires or bad injectors, please post here.

[instantfury]

im at 152k now. stock 'cept for a drop-in filter. i unfortunately haven't done the timing belt either. plugs were done around 100k, i think.

[SBT]

Just thinking out loud, that you might have slipped 1 cog on your timing belt - given the age and the climate conditions where you are. You'd prolly also do well to check your inlet side pre- and post-turbo to see if there's any tears/holes or loose connections anywhere - again given the age/climate.

 

Presume you've double-checked all of your vacuum hose connections thoroughly - specifically have you checked the T-connector below the TMIC (famous for leaks/looseness at that location)?

 

May also want to check your IM to TGVs/Heads as well for any leaks there...especially since it sounds like it's more of a low idle/off-throttle issue.

 

I know it's frustrating, but it really is a process of elimination.

[instantfury]

I finally was able to install the plug today, and so far so good. I started it, let it fully warm up and took it on a slow drive. Good lengths of time in a higher gear and. Lower rpm with no bogging down or stuttering. Sooo I think I'm good.

[instantfury]

Annnd I was wrong. I guess I didn't run/drive it long enough. It's not as bad as it was, meaning it doesn't bog down at lower rpm yet but it does miss while idling. Also I noticed the higher up in the rpm. Range around 5000-5500 it stuttered. It's probably the timing belt, but any input would be appreciated. Thanks.

[instantfury]

haha ok. i was just driving down the road today thinking about how it sucks not being able to use my cruise control, when all of a sudden the cel goes away.... it drove fine the rest of the way home, 20 miles or so but when i got home and let it idle it was ok for about 30 seconds then it started to miss again. i just ordered the IC.

[e_NiNo]

miss fire cyl #4 at 5000 5500 RPM, the cat in the up pipe trouble

 

the dealer found my probleme... 65 PSI in back pressure at the )2 sensor and normaly it's 31 psi MAX ...

 

the up pipe cat are stuffy

[ERLoft]

Finally got my car back yesterday. New shortblock, turbo, drive belts, plugs, gaskets, head studs, coolant hoses, oil lines, oil pump, water pump, etc. Also had them do the clutch & flywheel while the engine was out of the car and some minor maintenance stuff like power steering flush, HEPA filter, replace a couple of hoses under the hood and had them install a new Optima red top battery. (I have a hook up for wholesale price on that, so it was $40 less for an Optima than an OEM Subaru battery...)

 

Car seems to be good, although I have to baby it through the break in period. 1k miles at max 4k rpm, then slowly increasing rpms from there... Guess I'm just going to leave it in "I" mode through break in, and have a stock style map on the ECU for now, lol... I also had them remove the SPT intake and reinstall the stock airbox with a K&N panel filter...

 

Total out of pocket out the door was just over $3900. I figure that's not too bad all things considered.

 

Once I'm caught up, maybe in the fall, now I'm thinking about going to a BNR billet 18g.

[SBT]

That's a great price for all of that. Presume that Rick did the work?

 

Break-ins are tough - patience grasshopper...

[instantfury]

got my problem fixed. there was a crack in the IC housing, i didnt see it when i replaced the plug for some reason.

[ERLoft]

Yes, Rick did all the work and I can't really complain about the price. I definitely have patience going on for the break in period - no sense in screwing up the engine long term by not allowing the rings adequate time to seat properly! In a month or so, I should be out of the primary break in period, so I think I can hold out that long...

[jhig]

Having a misfire in cylinder #2. I just replaced the injector as that seems the most common issue but its still running the same. It's shaky at idle and almost stalls when I stop once in a while. Any ideas what I should replace next? What is the IC?

[splattypus]

1996 Legacy GT. I have been having a cylinder 4 misfire for going on 2 months now. I replaced wires last summer, then after the first misfire about 6 weeks ago, I have done plugs, coil pack, and most recently the injector. All was good for about 150 miles after the injector and then this evening did it again within about the first 2 miles of driving. I am at my wits end right now and running out of money. Any suggestions of possible causes are more than welcome. Only thing I can figure is maybe my computer is shot.

 

Please help a newbie out. Thanks

[instantfury]

It's the ignition coil. I had a crack in the plastic housing above the boot. Similar symptoms.

[splattypus]

Well I just replaced that 2 or 3 weeks ago, but that's definitely what its acting like. Its possible I got a faulty one. I dropped it off with the mechanic this morning, gave him the full rundown, so we will see where it goes, but that is definitely the direction he was leaning too.

[c_W_j]

and my situation fits gathermewool's to a tee.

 

intermittent check engine light when I first got it a year ago seemed to go away, then came back in cooler weather, eventually permanently through winter (I'm in NY most of the time). it's started back being intermittent as we vacillate between warm and cool daytime temps. Today, ran it up to 4-5k while merging back onto highway (and I have been having a bit more "fun" with it lately) and got a misfire in cyl#4 code.

 

saw somewhere claiming that it's a faulty sensor throwing a fake code.

 

I just want to be able to drive back and forth for work without damaging anything...

[splattypus]

Yeah that sounds about like my problem too. I told the mechanic to look into the important sensors. Haven't heard back from him yet, but hopefully he will find out whats up.

[eb50]

P302, 303, and 304 all at once. Car seems to hesitate unless i go hard on it. I am getting boost so thats good.

 

Cleaned the MAF, air filter, and did lucas injector cleaner. see if she runs better tomorrow.

[cd_legacy]

My idle started to get progressivly worse and the P0304 code came up. It seemed to be inconsistant and worse in the rain. (???) Anyway, my first check was all the vacum lines and wire connections at the MAF, coils, and injectors. Everything fine. My next attempt was changing the plugs with the OEM NGK's. Still no fix. Next I swapped coil packs #2 and #4 to see if I had a bad coil and if the code would jump to cyl #2 but it didn't. Finally I assumed, after research on this site, I had a bad injector and I ordered one from the Subi dealer and replaced it today.

What a change! The car idles as smooth as glass and no miss fire code on cyl #4! and the car runs much stronger when accelerating.

 

Seems to be a common problem with the LGT's and WRX's.

[DosRenshos]

The car has always idled rough but i got P0302 two days ago. I didn't have time to sort it out myself so i dropped it off at the dealer. They found nothing obvious. i had done new plugs about 6K ago with no discernible change. Leakdown was good to very good but comp test was roughly 1. 140# 3. 130# 2. 120# 4.120#. I'm a little concerned about the spread.

 

 

 

The dealer said that there was possibility of a burnt valve. Code was cleared and the car seems to idle and run fine so i guess we'll see...I may try to get into the cylinder thru the plug hole with my bore scope to see if i can see anything.

 

 

My question is what does the ecu look at and use as a trigger for the code?

[jpicheva]

Funny thing - ours never threw a code until well after the idle issues started. Not until it threw codes P0302, P0304 did the shop really do anything. We had fouled injectors and burnt valves on cylinders 2 and 4.

[Scooby2.5]

Add me to the list, of misfires and changed injectors over the last few months which seemed to help and even car ran pretty good until Friday.....

 

Motor is toast, only 30 psi in cylinder 4, pretty sure it is a valve issue. I guess I should feel lucky, 158,000 miles.

 

My subaru buddies keep telling me that if you don't crack the ringland then the number 4 exhaust valve is the other problem

 

Also why we were at it we checked number 2 since its on the same side and it was at 120 psi which is low.

 

So car is being trailered to Cobb plano for them to put the new short block and rebuild the heads.

 

 

I firmly believe the problems with number 4 are due to fuel starvation, and number 4 leaning out causing detention and heat from the lean condition.

 

They told me (great mechanic friends of mine at local dealer) they see this all the time.

 

1. Burnt exhaust valve in turbo cars #4

 

2. Head gaskets in N/A 2.5 cars ( you should see the head gasket they are using on the non turbo's now. Its a JOKE)

 

3. Failed ring land on number 4 turbo cars.

[mbeadon]

Another me too. 05 LGT manual transmission @82000 miles.

 

About a month ago I got P0302 MISFIRE CYLINDER 2 and P0000 PASS CODE (NO DTC DETECTED).

 

Assumed/hoped it was bad gas since my tank was nearly empty. Cleared the code and ran fine another 3 wks before getting the same codes again. This time I cleared the codes and flashed back to stock (I was running an infamous tuned ECU).

 

Another week and I got the same codes again. Tank is full of "premium" California gas.

 

It seems like the consensus is to swap the injectors and if that doesn't help to clean the MAF. I don't know how to do either but I guess that's why I bought the service manual... Any tips on how to proceed?

 

The MAF = Mass air flow and intake air temp sensor I found that in FU(H4DOTC)-27. Removal appears to be easy, what should I clean it with?

 

The injectors = fuel injectors I presume? Found those in FU(H4DOTC)-29. Do I really need to remove the coolant tank? ugh I hope not. New o-rings also seems overly anal but what do I know?

 

Thanks in advance for any suggestions.

[Guest PeteAWD]

Pulled those codes from my OBD II the other day. I have to tell all of you, and I have had the car since it was brand new, the vacuum hoses will blow or fall off, especially if you drive it aggressively and as the car gets old. These issues will be noted at idle but not at throttle. P0302 P0303, I found in the front of inter-cooler, underneath, there is a small blue t-joint and the hose connected to that falls off from time to time, the idle will be rough and misfire codes will begin. I also found the hose off in the front of the intake (has a small white disc with foam between the hoses), that falls off. Subaru parts told me it was just considered a hose to the vacuum sensor, there was really no name for the part. I get a P0303 code every week. Private tech and Subaru tech checked plug:NO, injector:NO, wiring harness coil pack:NO. Subaru tech said it was a floating valve, I said bullshit, the car does 120 mph, strong, like nothing. In any event, I think I found another hose off below the intercooler and the aforementioned hose attached to the blue t-joint I just explained. It feels loose but I cannot see where it ends. I am taking it to my private tech, hopefully he'll have some special mirrors to see it. The hoses below the intercooler and intake are NOT easy to get to. Need a cool engine, small hands and or a good variety of needle nose pliers. I'll advise on this other hose after it comes out of the shop.

 

*2005 Must use 91 octane or higher it will not run smoothly without it.

 

"Oil alone is not enough, use Lucas Oil Treatment!!!!"

 

Having a misfire in cylinder #2. I just replaced the injector as that seems the most common issue but its still running the same. It's shaky at idle and almost stalls when I stop once in a while. Any ideas what I should replace next? What is the IC?

Edited July 6, 2011 by PeteAWD

[Scooby2.5]

Mine ended up being 30 psi in cylinder four

 

If you are having misfires, I would get on it immediately by trying injectors and coil packs and if that doesn't fix it better do a compression and or leak down test.

 

These motors are having problems with exhaust valves not sealing at or near 100k. They get out of spec and because they are not sealing fully the valve gets hot and eventually burns.

 

I fought misfires for quite some time and finally got an injector changed (shouldn't have waited so long) and it ran PERFECT for two weeks and then the motor went.

 

My symptoms were massive misfires below about 2300 rpm or so, but above that it ran fine.

 

Im pretty sure its an exhaust valve or ringland, but I will know for sure when Cobb Plano gets the motor apart.

 

Good news for me was, I had about 160,000 miles on my car before it finally went.

 

 

 

Add me to the list, of misfires and changed injectors over the last few months which seemed to help and even car ran pretty good until Friday.....

 

Motor is toast, only 30 psi in cylinder 4, pretty sure it is a valve issue. I guess I should feel lucky, 158,000 miles.

 

My subaru buddies keep telling me that if you don't crack the ringland then the number 4 exhaust valve is the other problem

 

Also why we were at it we checked number 2 since its on the same side and it was at 120 psi which is low.

 

So car is being trailered to Cobb plano for them to put the new short block and rebuild the heads.

 

 

I firmly believe the problems with number 4 are due to fuel starvation, and number 4 leaning out causing detention and heat from the lean condition.

 

They told me (great mechanic friends of mine at local dealer) they see this all the time.

 

1. Burnt exhaust valve in turbo cars #4

 

2. Head gaskets in N/A 2.5 cars ( you should see the head gasket they are using on the non turbo's now. Its a JOKE)

 

3. Failed ring land on number 4 turbo cars.

[system60]

Have codes for misfires for all 4 cylinders and lean bank for Cyl1. Cars idle got worse and worse over the coarse of a day before the CEL came on. Just went stage2 a month and a half ago, install and tune were performed by a dealer which at the same time I also had the plugs changed since I'm almost at 60k. Been taking it easy at the car gave a quick look over loose vacuum lines or loose clamp on the hoses for the TMIC but yielded nothing. Will be giving it a more thorough look over tomorrow and give the MAF a cleaning. Already have an appointment with the dealer for monday if things don't get better tomorrow.