97 Outback misfire 3&4

[doc526]

Thank you for the correction Gloyale. I did read some about shimming the valves but did not realize that it pertained to the EJ25 too.

 

Dean

[Gloyale]

Thank you for the correction Gloyale. I did read some about shimming the valves but did not realize that it pertained to the EJ25 too.

 

Dean

 

IIRC, The only subaru engine to use buckets and shims is the DOHC EJ25

[johnceggleston]

 

The chronic misfire problems I've seen were all caused by interference between the Plug wires and the Injector wires.

 

Get some flexible harness loom cover (the corrogated stuff for wiring harness), and put it around you're plug wires where they are nearest the injector pigtails.

 

would this be caused by crappy plug wires, or re-routing plug wires, or both.

 

or something else. i know it didn't come from the factory that way.

[Gloyale]

would this be caused by crappy plug wires, or re-routing plug wires, or both.

 

or something else. i know it didn't come from the factory that way.

 

Well alot of factory EJ25s did actually come with a piece of hard corrugated shielding on the wires.

 

Really good quality replacement wires have them on there too.

 

I think as the computers get more and more sophisticated and capable thorugh teh years......the more common the misfire codes are.

 

I don't know why......but I've gotten cars with this same case.....over and over......and the misfire codes ALWAYS go away with good shielded wires, some extra tape around the injector pigtail, and seperating the two.

[ccrinc]

I talked to a guy who is the Assistant Service Manager at a major Subaru dealer here in Denver, hoping to see if Subaru has come up with any resolution to the problem, because it's all over the internet. And because that CEL lit up on my dash is annoying me too.

 

He told me that he has seen it repeatedly and "wishes Subaru would come up with a software upgrade" to fix it. It is interesting to note that SOA says the fix is to replace the ECU, but many people have done that and it's no help.

 

It appears that the problem is not (usually) with the plug wires, sensors, fuel, plugs or any of the other commonly replaced parts, but a far bigger issue with the programming of that model year ECU.

 

If you research this problem thoroughly, there are thousands of complaints and NOBODY has any idea how to permanently fix it. Subaru has no reason to try to address the issue because the cars are over 10 years old and way out of warranty.

 

It's electronic guys. You can keep throwing money at it or live with it. That's what I personally am going to do on my car.

 

Emily

http://www.ccrengines.com

[subynut]

So, it IS the computer. That's the pits. I've wondered about it for quite some time, but those things are not cheap for a test, ya know?

 

Well, it looks like the outback will have to live in non-emissions testing country for the rest of it's life and will gut the cats since the engine will be running rich (limp home) most of the time. Which is fine, as long as we stay here.

[Quidam]

"I don't know why......but I've gotten cars with this same case.....over and over......and the misfire codes ALWAYS go away with good shielded wires, some extra tape around the injector pigtail, and seperating the two."

 

Bump.

 

Edit:"When electrical energy is flowing through a conductor it will tend_because of a property called inductance_to create an electrical impulse in any other conductor that happens to be close by. This phenomenon is used in the ignition coil_which is a step-up transformer_ to create the high secondary energy that is delivered to the spark plugs."

 

"The same thing can happen in spark plug wires that are very close to each other. As the elecrrical pulse moves down one wire, it can induce a secondary_though considerably smaller_pulse in the second wire."

Edited February 6, 2010 by Quidam

[ccrinc]

"I don't know why......but I've gotten cars with this same case.....over and over......and the misfire codes ALWAYS go away with good shielded wires, some extra tape around the injector pigtail, and seperating the two."

 

Bump.

 

Edit:"When electrical energy is flowing through a conductor it will tend_because of a property called inductance_to create an electrical impulse in any other conductor that happens to be close by. This phenomenon is used in the ignition coil_which is a step-up transformer_ to create the high secondary energy that is delivered to the spark plugs."

 

"The same thing can happen in spark plug wires that are very close to each other. As the elecrrical pulse moves down one wire, it can induce a secondary_though considerably smaller_pulse in the second wire."

 

I admit that there are probably cars of which this statement is true. In the case of my car, those have all been addressed, and whenever I am doing about 65mph on a highway the CEL will flash and then remain lit.

 

When you've done every test and fixed every possible issue, what remains must be true. Paraphrasing Occam's Razor.

[Quidam]

Yes, induction is but one possibility.

 

The good thing about Gloyal's finding, is that it's repeatable and something people can try...all over the world. It's also quite likely that it happens.

 

I'm pretty sure a lot of people never consider it. It's the reason late model Subaru's are picky about plug wires. Subaru calls it "misfire". One and Three are next to each other in the block. 2 & 4. Fire one after the other, the plug wires run close together. Think of the poor old EA-82T:) Lots of boost, bad cooling system. #3 is where the gasket and head crack problems start, by the turbo (heat), induction by #1. Same thing with #2 induction to #4. I have another 140K EA-82T I'll be looking at this summer.

 

"This is really a giant problem when the two wires happen to be consecutive in the firing order! In other words, the current flowing to one cylinder can induce a secondary voltage strong enough to prematurely ignite the next cylinder in the firing order."

 

"This is one of the worst forms of detonation." And I agree.

 

Doug

 

Higher compression ratios...It's more likely to show up. It can and does happen in distributor caps...why they got larger over the years. Crossfire happens too.

 

In a small block Chevy, number five and seven are consecutive in the firing order, and next to each other in the block. People chased "induction irregularities" and "lean in #7" until it was sorted out.

Edited February 6, 2010 by Quidam

[Cougar]

It might not help but going over the engine and chassis grounds and cleaning them may clear up excessive noise problems in the electrical system that may be causing the trouble. It has helped some folks in the past with issues like this.

[subynut]

Last time I drove it, I noticed it has a hard time holding 25mph in 5th gear. It used to be able to maintain that speed and as long as you didn't give it too much throttle, it would accelerate from 25 in 5th - not fast, but it didn't mind it. Now, it says "Don't even THINK about it!" I'm sure Subaru didn't design it to run that slow in 5th, but it certainly used to be able to do it. My 86 wagon could do 25 in 5th with either the original ea82 or with the ej22 I had in it and the rpms in 5th are identical between the two cars.

Just a few more pieces of the puzzle

[idosubaru]

If it is the ECU then that's an easy fix isn't it? Perfectly fine running EJ25 ECU's are a dime a dozen. I have at least one...if not more, but normally I scrap them because they're so cheap and easy to get due to low demand and high supply. They almost never fail.

 

Junkyard database shows 500+ units available for the 97 OBW alone...start adding in other models with the EJ25 and other years and there's thousands of ECU's starting at $25.

 

I have a 1997 EJ25 ECU that never gave a misfire when I drove it (with two different engines pre and post engine swap). So this ECU would fix all of these issues? I'm willing to mail it to you Emily but I would think you have plenty of ECU's to play with, swap, and test out - have you done that already?

[Quidam]

subinut,

 

That puts a load on the engine, lugging it. 25 in 5th type stuff puts a load on the thrust bearing.

 

Doug

[subynut]

Forgive me, Grossgary, but the cheapest used first gen ODB-II ej25 ecu goes for 175 bucks that's on the opposite end of the state. We have a whole woppin' one pull-a-part and it's 90 miles away and usually has, at most, 2 subarus. (What's odd, is this area is swamped with hondas and there's hardly any in the junk yards. Does that mean somthin? ) If Emily doesn't want that ECU, I would be willing to take it for testing purposes.

 

 

Quidam, I realise that can lug the engine, I certainly hear and feel when that happens - that's when I drop to 4th, but when I'm just maintaining 25 on flat ground, the cars don't mind. Well, the outback used to not mind, Now, it says, NO!

 

 

Well, back to my U-Joint adventures on my truck...........

[johnceggleston]

Forgive me, Grossgary, but the cheapest used first gen ODB-II ej25 ecu goes for 175 bucks that's on the opposite end of the state.

 

 

this guy has one he doesn't need, i bet he'd sell it for 30$ plus shipping.

 

http://www.ultimatesubaru.org/forum/showpost.php?p=899765&postcount=11

[idosubaru]

Forgive me, Grossgary, but the cheapest used first gen ODB-II ej25 ecu goes for 175 bucks that's on the opposite end of the state.

Flagstaff has one for $99 - 1-800-352-8737

 

i never go buy parts, my time is too valuable. i order what i want and have it mailed. waiting on my door step verses driving, waiting in line, waiting for them to find it. and as your numbers suggest it's usually much cheaper. you can order any number of the $25-$35 ones out there. of course I don't think the ECU will fix your problem so I can see why you wouldn't want to pay much but $30 is worth diagnosis to me, maybe not someone else.

 

you can PM me if you're interested in the one I have, but i probably can't offer it to you as I did emily. 1996 Automatic EJ25.

 

Good luck tracking this down, sure sounds frustrating.

Edited February 10, 2010 by grossgary

[Gloyale]

 

Quidam, I realise that can lug the engine, I certainly hear and feel when that happens - that's when I drop to 4th, but when I'm just maintaining 25 on flat ground, the cars don't mind. Well, the outback used to not mind, Now, it says, NO!

 

 

 

Well first off, 25 in 5th is just silly. You aren't saving any gas because you are operating the engine in a very inefficient range of it's powerband.

 

I had an arguement with my GF over this the other day. She yelled at me for drivng her van 50 in 3rd, accelerating onto the freeway:rolleyes: She say's "you don't have to floor it you'll use too much gas" I say "I was only half throttle, if I'd have shifted earlier I would ave had to open the throttle more to pull the taller gear. It's better to let it wind out a bit, with a steady, gentle throttle" (89 toyota VanWagon)

 

But that aside, you can sometimes get a bit more bottom end with a good set of new NGK plugs. My EJ was lugging and not happy below 2500 rpms till I cahnged the plugs.

[theidealist]

Hey, new to the thread, but awesome that it is so recent and has so many high-quality contributions. subynut, ccrinc, gloyale, grossgary, others -- all usmb legends!

 

The 98 OBW wagon (140k mi. - 5spd) I bought late last year is having similar if not identical issues. Cylinder misfire codes on 3&4 when engine seems otherwise running fine. Bucking (I assume this is when the whole car "bucks" or stutters heavily you as you are maintaining speed and the clutch is fully engaged). CEL light - oh yes.

 

I also have a "high idle" code to add to the bunch.

 

The engine was replaced by a previous owner, as confirmed in the maintenance records I was given, and by the mechanic who performed the HG (Head Gasket) repair one month after I got the dumb thing.

 

In my case I could care less about the CEL (Check Engine Light), although it does annoy me. Sure, I'd love to get rid of the error(s), but to me the most annoying thing is the bucking! That's what I want to fix. Makes driving the car intolerable at times.

 

Anybody got any ideas on how to diagnose and troubleshoot that?

 

I have not even been able to get it to the point where it will *always* do it when I do *such and such*. It is intermittent and severe, which is infuriating! The CEL light may or may not come on / flash at me when it's bucking. The engine temperature does not seem to make a difference. It seems to *maybe* be a little more likely to happen when the outside air temp is cool and/or wet.

 

I can tell when it is about to do it, because I feel the engine go into coasting mode (as if the gas has been removed) even though my foot is still on the gas, attempting to maintain the current speed. The car decelerates naturally, and then at some point, it kicks - bucks - back in as if I had the engine at 5k RPMs and dropped the clutch. It's like the ECU woke up and said "hey! This guy is trying to maintain speed, give it all we've got!" I'm learning sometimes I can feather the accelerator/gas pedal to get a smooth re-engage, but often this is just impossible.

 

It almost always happens when I am driving in the 2-3.5k RPM range, on level or slightly down hill. It has never done it when working to go uphill.

 

Sometimes the cruise control cannot even keep the car from bucking and get it to maintain speed.

 

I would really like to put together a list of things to check, and acronyms to help me.

 

Base on other research, this could be just about anything:

• Spark plugs (new NGK with HG repair)
  
• Spark plug wires
  
• Distributor (synonymous with coil?)
  
• Injectors
  
• TPS (Throttle Position Sensor)
  
• MAF (Mass Air Flow) Sensor
  
• ECU (Electronic Control Unit - a.k.a. the computer)
  
• IAC (I have no idea what this is)
  
• Fuel filter (just replaced, old one looked ANCIENT)
  
• I refuse to believe it could be the neutral switch/sensor, that is just too weird and unrelated.
  

 

Comments on others? Likelihood of given? I would prefer to diagnose over blindly replace as I don't have a lot of time or money and I hate replacing things that are working because in my experience you're more likely to screw something up replacing it than you are diagnosing it.

 

Any help/thoughts/flame is appreciated.

[Cougar]

The IAC is the idle air control. For the fast idle problem that is a good thing to check out. Also check for a vacuum leak. That can cause a high idle.

[subynut]

Yeah, I would check that IAC. Have you checked your grounds and the electrical connectors to see if something is loose?

 

Yes, that misfire code is very frustrating. I'm taking a break from it since it's making me nuts trying to diagnose the blasted thing. So, I replaced the front u-joints on my truck - Yay, no more squeaking with the hubs in!

[jcsvx]

OK we have fixed this problem on three different 2.5s in the last year

all three have had loose front balancers the bolts were tight but bottomed out in crank the key-way and key were worn and had to replace key on all three and new washer and shorten bolt one thread (grinder) the loose balancer causes noise and the knock sensor

retards the timing until it missfires and turns on cel. Hope this fix works for you too Joe

[outbackusjunkus]

OK we have fixed this problem on three different 2.5s in the last year

all three have had loose front balancers the bolts were tight but bottomed out in crank the key-way and key were worn and had to replace key on all three and new washer and shorten bolt one thread (grinder) the loose balancer causes noise and the knock sensor

retards the timing until it missfires and turns on cel. Hope this fix works for you too Joe

 

This thread is two years old, I'm sure he figured it out by now.

[Gloyale]

.........., but to me the most annoying thing is the bucking!

Anybody got any ideas on how to diagnose and troubleshoot that?

 

 

 

I can tell when it is about to do it, because I feel the engine go into coasting mode (as if the gas has been removed) even though my foot is still on the gas, attempting to maintain the current speed. The car decelerates naturally, and then at some point, it kicks - bucks - back in as if I had the engine at 5k RPMs and dropped the clutch. It's like the ECU woke up and said "hey! This guy is trying to maintain speed, give it all we've got!" I'm learning sometimes I can feather the accelerator/gas pedal to get a smooth re-engage, but often this is just impossible.

 

It almost always happens when I am driving in the 2-3.5k RPM range, on level or slightly down hill. It has never done it when working to go uphill.

 

 

 

Just fought this same ussue in a 97 outback.

 

it was a misadjusted TPS. Also made for odd high idling.

 

Basically, when coasting, at light throttle, the ECU is thinking the throttle is totally closed......which triggers fuel cut for coasting.

 

Doesn't do it up hill because you have a bit more foot in the throttle.

 

Have someone with a streaming data scanner check the TPS adjustment and correct it.

 

I garauntee that's the issue.

[subynut]

No, mine is still doing it. Just living with it. One downside: it has caused the cat to go and it is now whistling at full throttle. It now has over 230K miles and the rest of the car is showing it's age. We're having clutch and tranny troubles and the sun has destroyed the interior and it's working on the paint. So, I am pushing to get the car replaced.

[Gloyale]

No, mine is still doing it. Just living with it. One downside: it has caused the cat to go and it is now whistling at full throttle. It now has over 230K miles and the rest of the car is showing it's age. We're having clutch and tranny troubles and the sun has destroyed the interior and it's working on the paint. So, I am pushing to get the car replaced.

 

Adjust the TPS