Cylinder misfires or bad injectors, please post here.

Eesh, looks like misfires are more common than I expected. Anyways I've got random misfires on my 97 leg gt wagon since I've owned the car a few months back. Here are the deets:

-At first it was always all 4 misfires and a fuel trim P0170 but mechanic told me once all 4 misfires twice the P0170 code comes on. Perhaps the reason why it blinks now and then. Now it's random order but i'm clearing the codes once it comes on.

-Always comes on at cruising highway speeds. This is the latest freeze-frame- Calc load 26.2%, eng coolant 190F, STFT Bank1 0.7%, LIFT Bank1 15.6%, Intake Mani press 18.0 in.hg, eng RPM 2850, Speed 64MPH

-Smells of sulfur, i'm pretty sure the cat's being burned up, light smoke after prolonged driving. Replaced primary cat but smell has come back.

-Just recently bogs/shakes a bit on first gear from stop like as if I didn't know how to drive standard, but only sometimes. But that might be an unrelated problem.

-So far we've changed spark plugs, front and rear O2 sensor, coil pack, wires were changed from the previous owner, fuel filter, ran TKO for fuel injectors. Nothing shown with leakdown test. Patched up all exhaust leaks. Still need to go through sensors and compression test.

Wondering if any of you guys have a clue. I just don't know why it's only happening at highway speeds under no acceleration. Thanks in advance.

Update on my issues. 2005 Subaru Legacy GT ltd. To recount, I was having rough idle, and "lugging" at low RPMs (sub 3000) when accelerating. Seems OK when RPMs get past that. I am getting a misfire in #4 cylinder.

So far I have:

replaced injector

cleaned MAF/IAT

Replaced Air Filter

Swapped Coil Packs

Checked Blue Tee Vacuum Lines

Had compression check (all > 130)

Replaced the orange o-ring between the intake manifold and TGV

I really have no clue where to go next??? Any help is appreciated. Maybe I have been looking at the wrong cylinder. I am looking at the cylinder closest to the driver (rear of engine bay, drivers side in North America). I really don't know what else this could be?? HELP!!

bad intake/exhaust valve? might be sticking-- i had the same problems you have but i drive an 07 with 100k miles. when you replaced your injectors did you use all new gaskets/orings? my misfire code for cylinder #4 hasnt come back yet since i have thrown in a new injector along with a new lower injector gasket.(this is because subaru didnt include one, bought it from friedbean) also seafoam will help those sticking valves.. my car runs a bit smoother. idles better. ( Take a look at you bpv and IC -- any cracks? ) watch my cel come back as soon as i hit submit reply.

Good luck

Update on my issues. 2005 Subaru Legacy GT ltd. To recount, I was having rough idle, and "lugging" at low RPMs (sub 3000) when accelerating. Seems OK when RPMs get past that. I am getting a misfire in #4 cylinder.

 

So far I have:

 

replaced injector

cleaned MAF/IAT

Replaced Air Filter

Swapped Coil Packs

Checked Blue Tee Vacuum Lines

Had compression check (all > 130)

Replaced the orange o-ring between the intake manifold and TGV

 

I really have no clue where to go next??? Any help is appreciated. Maybe I have been looking at the wrong cylinder. I am looking at the cylinder closest to the driver (rear of engine bay, drivers side in North America). I really don't know what else this could be?? HELP!!

bad intake/exhaust valve? might be sticking-- i had the same problems you have but i drive an 07 with 100k miles. when you replaced your injectors did you use all new gaskets/orings? my misfire code for cylinder #4 hasnt come back yet since i have thrown in a new injector along with a new lower injector gasket.(this is because subaru didnt include one, bought it from friedbean) also seafoam will help those sticking valves.. my car runs a bit smoother. idles better. ( Take a look at you bpv and IC -- any cracks? ) watch my cel come back as soon as i hit submit reply.

 

Good luck

ANy tips on how to use the Seafoam? SHould I just put it in my fuel for a while, or treat the engine in some other way.

well my cel misfire cyl #4 is back.

you can youtube seaform for application use.

ANy tips on how to use the Seafoam? SHould I just put it in my fuel for a while, or treat the engine in some other way.

I have now had a leakdown and compression test and all was fine. All cylinders were 130-140 psi.

 

P0304 CEL Light has come back on. When the shop did the compression test, they said that the new injector that had been installed was leaking from the top, so they put a different one in. The car now runs and idles much better (though not perfect), but the code is still being thrown!!!

 

I have no idea where to go from here? If someone can suggest I would appreciate!

 

Thanks

I took my car in again, this time to the dealership. THey said I had only 95 psi compression in cylinder 4?? So one shop said compression was fine, the other said it wasn't. My question is is there a way for an intermittent compression problem that may mean that the valve is gummed up in some way, but not burnt? Is it possible to get away without a valve replacement, and just a seafoam treatment or something instead? Can I get this POS running well again without laying out $2k????

i'll tell you as soon as i get the bill-- it is in the shop now to replace the valves, with a cylinder 4 misfire , compression came back at 74psi. all others are fine. i will be doing just the side that has the problem.

BTW Curious what others have paid to replace a burnt valve, and whether they replaced all 4 or just the two on the side with the problem????

So is it advisable to replace only one stock injector if you are recording P0302's?

Mine moved from P0302 to P0304 after I swapped.

thanks

Eesh, looks like misfires are more common than I expected. Anyways I've got random misfires on my 97 leg gt wagon since I've owned the car a few months back. Here are the deets:

 

-At first it was always all 4 misfires and a fuel trim P0170 but mechanic told me once all 4 misfires twice the P0170 code comes on. Perhaps the reason why it blinks now and then. Now it's random order but i'm clearing the codes once it comes on.

 

-Always comes on at cruising highway speeds. This is the latest freeze-frame- Calc load 26.2%, eng coolant 190F, STFT Bank1 0.7%, LIFT Bank1 15.6%, Intake Mani press 18.0 in.hg, eng RPM 2850, Speed 64MPH

 

-Smells of sulfur, i'm pretty sure the cat's being burned up, light smoke after prolonged driving. Replaced primary cat but smell has come back.

 

-Just recently bogs/shakes a bit on first gear from stop like as if I didn't know how to drive standard, but only sometimes. But that might be an unrelated problem.

 

-So far we've changed spark plugs, front and rear O2 sensor, coil pack, wires were changed from the previous owner, fuel filter, ran TKO for fuel injectors. Nothing shown with leakdown test. Patched up all exhaust leaks. Still need to go through sensors and compression test.

 

Wondering if any of you guys have a clue. I just don't know why it's only happening at highway speeds under no acceleration. Thanks in advance.

Just in case anybody had the same symptoms, here's an update. I did the DIY grounding mod since I noticed headlights dimmed and figured why not.. and it fixed it! Used to get mf's after about 30 kms/1 day, and now it's been a week with no CEL. Car runs wayy smoother too, 1st gear hesitation doesn't happen and headlights/dash lights don't dim anymore. I'm thinking bad grounding was playing around with sensors, or the coil pack wasn't getting the right amount of power.. anyways who knew this would fix it... I'm a happy camper.

I felt it appropriate to post as I used the advice gathered on this thread to solve my issues. About 3 weeks ago my subie started acting up a bit by having a bit of a twitch in the throttle in 1st gear. I kind of chalked it up to miles (152,000) but the car always has run perfect otherwise. I did a brake job Sunday and then Monday on my way to work all hell broke loose and the car ran like absolute crap. Symptoms led me to believe the clutch was going but then it started misfiring badly. I had it scanned and got the P0302 code after I opted out of the $1900 quote I got from a local Subaru dealer (shame on them). I picked up some new plugs (NGK) and a new wire set (NGK), did the install myself, and voilla.......she runs better than ever. I am glad that I did not have to dive into the injectors, coils or any more significant repair.

I am glad I trusted my gut and not the dealer. The plugs were just due for replacement at their 60,000 mile interval. I attached a couple of pics to show what the old plugs looked like. There were a couple that appeared to be pretty shabby looking, and I suspect the last mechanic that installed the plugs wrenched on a couple of them a bit too hard. All is good now though.

I have had another leakdown test and now it appears as though something is drastically wrong. My # 4 cylinder seems to be leaking into the PCV, I haven't got the numbers from the shop but leakdown loss is greater than 30% in cylinder 4 and fine in the others. No sound from tailpipe or intake, but gurgle from pcv/oil.

What does this mean and what kind of repairs am I needing?

I have had another leakdown test and now it appears as though something is drastically wrong. My # 4 cylinder seems to be leaking into the PCV, I haven't got the numbers from the shop but leakdown loss is greater than 30% in cylinder 4 and fine in the others. No sound from tailpipe or intake, but gurgle from pcv/oil.

 

What does this mean and what kind of repairs am I needing?

ringland failure

new engine

That seems quite drastic, but I read a little bit and engines don't seem that expensive.

Do I risk any damage to my vehicle if I continue driving in its current state? If the block, pistons etc are going to be replaced in the future, can anything go wrong and damage something else?

Is there some way I can get something for my engine? Are there rebuilt ones out there?

OK Thanks,

If I continue driving it do I risk damage to something I wouldn't be replacing anyway (ie I don't really care if I mess up the pistons or heads do I?).

Is there some known way of getting some $ back for the block that you tae out? Seems like shouldn't be too much work to fix this once the engine is all out. On that note, is there rebuilt blocks or not worth it?

Dont bother with a rebuilt block. For the price of a brand new shortblock it saves downtime and atleast you know it was assembled right. You can try and sell your old block for a couple hundred on here.

Do you consume oil at all?