97 Outback misfire 3&4

[subynut]

Hi guys,

 

I drove my Dad's 97 Outback (EJ25, 5sp manual, all stock, 207K on the clock) today and boy was that an experience! I got the misfire on just cyl 3 today, however, dad has been complaining that it usually complains about 3 and 4 on every drive. Plugs are Subaru new, same with the wires.

Now onto the interesting drive to work today: When I fired it up, all seemed normal: running at about 1700 till I touched the throttle then every time I pushed the clutch in it would climb to 3k then slowly work it's way back to about 1000. Once it warmed up, the idle was slightly rough at ~650. It bucks (sometimes quite violently) with the throttle just off the idle switch whether it's warmed up or not. While driving in the 2-3k rpm range at light throttle (trying to keep it from bucking), the check engine light was blinking away at me. Now, during that time it was blinking, it felt fine - did not feel any hesitation whatsoever. But the computer thought there was something wrong. I checked the codes when I arrived at work and it had 1 count of a misfire on cyl 3.

 

A little history:

The car has always had a slight hesitation right off idle - annoying, but "within reason". Car gets excellent mileage: 25 all city, 30 out on the highway, ~27 mixed.

The head gaskets blew and made a royal mess about 20K miles ago and we swapped the engine. Ever since I pulled that thing, we have have had the misfire on 3 and 4. Although, it was very rare and usually happened under very harsh driving or very long freeway runs back then. Now, if your in the 2-3K rpm at part throttle, that CEL will blink and blink and blink. When you check the codes there is usually one count of a misfire on 3 and 4. Never 1 or 2. The CEL will stop blinking if you go to WOT and sometimes will go out if you stay on the floor long enough. - that don't make any sense!

I have checked connections, traced wiring thinking I pulled something during the swap, I have checked for vacuum leaks, checked the impedance of the coil pack: within spec - may try swapping it with another I have laying around to see if anything changes, Cleaned the MAF - had my mechanic check it and he said it was within spec. O2 sensors are no older than 5k miles and from Subaru. I talked to the techs at CCR and they have no idea. I tried calling that Suby specialist place (can't think of the name - they were at WCSS9 with that white high mileage 1st gen legacy) and they said without driving the car, it's very hard to diagnose over the phone. Which I can understand - I have the same issue trying to fix a computer over the phone. Could the computer be on the fritz? Although $250 is a rather expensive test since the wrecking yards won't take them back - none within a 200 mile radius.

What I don't get is why when the car is running it's roughest, the computer doesn't throw any codes, whereas when it drives fine, the CEL blinks it's way to the next county!

Any brilliant ideas?

 

Thanks,

Ted

[subynut]

Ok, I swapped the coil pack from the EJ22 off my wagon and the idle is a little smoother than before, but I couldn't do any more diagnosing due to time constraints. What's the difference between the diamond coil pack and the Hitachi coil pack?

I did hook up a vacuum gauge to it and it's pretty stable at about 15.5" It has just a little bit of flutter when the cooling fan kicks on/off. I revved the engine and held it there in the RPM range that the misfire code would trip and the vacuum is solid - no fluctuations whatsoever - ~17" depending on how much throttle I was using and, of course, the check engine light stayed off.

I did notice a slight valve tap from both haeds, donno if that could cause a misfire or not. Does the EJ25 DOHC have solid lifters or hydraulic?

Mom and my sister are taking the car to Phoenix, ~170 miles away, wish I could drive so I could gather more data, but I must work that day.

 

Some more data to chew on while I diagnose this quirky thing.

 

Thanks,

Ted

[doc526]

I have the same problems (bucking and missifre) except I only have a 1&3 misfire. Mine is a 97 OBW 5sp 2.5 with approx 175K miles. I do not know if the motor has been replaced or not as I am not the original owner.

 

The high revs when you push in the clutch seem to be the norm. Mine does the same when cold.

I believe that it has to do with the fact that the engine is not warmed up and the A/F is slightly richer and there is no load on the motor like an auto trans equipped car to keep the revs down while coasting with the clutch in.

 

The bucking thing I am still working on. It happens intermittently and the only way I have found to control it was by depressing the clutch and adding a little more gas. One theory that I have (and I am probably wrong:-\ ) is that we can catch the motor at the wrong time in the firing sequence while letting the clutch out and make it stumble, which can cause the missfire light. I have had it throw a missfire code once when I bucked it.

 

Other wise the missfire continues to elude me. Most of my coded have occured while steady speed driving on the interstate. I have reset codes and had them appear in as little as 200 miles and as long as 6K miles. Plugs and wires are good ( just checked them just before thanksgiving).

 

Other than that, mine like yours runs perfectly. Mileage is about 25-26 mixed driving.

 

 

Sorry I don's much insight as I am still learning about this car. Hope what I have wrote helps.

 

 

Dean

[subynut]

Ahhh, but that tells me I am not alone!

Yeah, I don't understand how when it's being stupid, the light is out, but when things "feel" normal is when the computer has a fit.

[doc526]

Ahhh, but that tells me I am not alone!

Yeah, I don't understand how when it's being stupid, the light is out, but when things "feel" normal is when the computer has a fit.

 

I know. :-\

[subynut]

Does anybody know if there is a DIY device that allows you to monitor all the parameters and sensor readings while your driving in a OBD-II Subaru? If I had some sort of data loging maybe I can see what is going on and get a better idea in diagnosing this quirk.

 

Thanks

Ted

[kemmer]

This is exactly how my current woes started. It is now to the point that the car is barely drivable, but like you said, once you're moving it's fine. The gas mileage is fine. I took it to a shop and they spent several hours looking for the issue and couldn't find the problem. I took it to the dealer and they finally came up with low compression in one cylinder and high in another. The third misfiring cylinder was normal and they didn't test the cylinder that wasn't missing.

[doc526]

I saw this from another post and thought you might be interested in it. I am thinking about getting it to check my brother-in-laws car (pontiac) that is having MAP issues. Plus it looks really cool........

 

 

http://search.store.yahoo.net/cgi-bin/nsearch?catalog=yhst-49187380673845&query=scangaugeII&searchsubmit=Go&vwcatalog=yhst-49187380673845&.autodone=http://www.rallitek.com/

 

 

Subynut, did notice one thing with the bucking issue. I found that it went away when the car was fully warmed up (according to the temp gauge at least). It only seems to occur when the idle was high during shifting while cold.

 

Dean

Edited January 18, 2010 by doc526

[subynut]

Thanks Dean, I will look into that unit some more. I wonder if it is just for Subarus of if it is universal....gonna have to check it out.

 

As far as the bucking, it does not change whether it is warmed up or not. If the air temp is cold, it's worse, but not engine temp.

I swapped the MAF with a known good one and reset the computer and will see how it runs.

 

Thanks,

Ted

[doc526]

I believe that it is universal as it uses the OBDII port.

 

Good luck on your test. I am interested on what you find.

[ccrinc]

I recently acquired a '97 OBW, 5 speed Limited (really nice!) and am using it as my daily driver. Naturally, it has a freshly reman'd EJ25 in it.

 

From day one, the CEL has been doing exactly what you describe. But the car runs perfectly, even with the 1&3 misfire.

For a few days, I had very high rpms at idle (both cold and warm), and we replaced the IAC. That cured that problem, but didn't help the 1&3 misfire.

 

I have "heard" that there is/was a recall on this vehicle for the neutral safety switch which "could" cause these issues, but due to personal conflicts, I haven't had a chance to look into it.

 

As soon as we find out a reason and cure for this, I'll post it up here. (The owner's wife's car...you can be sure the issue will be resolved! )

 

Emily

http://www.ccrengines.com

[subynut]

Emily! Long time no hear!

 

I'll look into the IAC to see if that helps the funky cold idle.

 

NSS....that would be interesting if that is what was giving us the grief. Makes you wonder how much the ECM assumes, eh? EPA controlled fuel injection - works great, when it works!:-\

 

As I kinda figured, the MAF didn't make any difference. But, I had it laying around and figured why not?

 

Will keep you guys and gals updated

 

Thanks,

Ted

[doc526]

Thanks for the updates. If I get the chance to pop the hood this weekend, I will check my IAC. I will let you all know too if it affects the cold idle if it is in fact dirty.

 

My 1949 Ford project truck is yelling at me to get some work done since I have been neglecting it. Hopefully it will be on its' own wheels by this weekend.

 

 

 

Dean

[outbackusjunkus]

This happened to me this fall, missfire on 2 cylinders at once (can't remember which ones). Ended up being crapped out injectors on both. By the way, 2.2 and 2.5 injectors are interchangable.

[subynut]

Yes, I had them checked. 3&4 were fine, 1&2 were out of spec, so, go figure! But, no difference. I'm going to inspect the neutral switch and it's wiring when the weather eases up: 40-60MPH winds and temps in the 40s makes it difficult to work on the car.:-\ Good thing though, it may snow on the weekend so, in the mean time, I'll get to go romping in my truck!

['84 Flat-Four]

Just want to throw this out there... have you done the water spray test? Best to do it in the pitch black darkness, engine at op temp, and with your eyes adjusted for the dark. Use a spray bottle to mist the water. Spay the wires and coil.

 

Reason I throw this out there is cause I was chasing a misfire on #2 for a couple weeks. Then yesterday #2 & #4 misfired badly. I sprayed it down and after a few seconds it was like chinese new years in the engine bay. All four wires and the coil sparkling like mad at different points.

I noticed that it took a few seconds to sparkle and I had to really stare at it in the dark to see the sparkles.

 

If I'm stating the obvious and you've done it, then ignore me. But it may be worth trying if you haven't.

 

I getting a new coil and wires from the dealer today.

Godd luck!

[subynut]

I have not done that, but will do it once the weather calms down. (had no power from 6:30 till about 11 last night - really bad winds!) I have watched it in complete darkness and have had my hands in the area to feel any leakage (not the best way since those sparks are strong and really hurts when you get hit) and did not see or feel anything, my mechanic did some testing and he did not detect any spark leaks either. From listening to the engine, there is a very small stumble, but all our Subarus have a minimum of a small stumble....in fact, my truck has a small stumble and it's got 10 cylinders!

 

During one time while letting the engine warm up via idle, I did have the engine light blink at me while it was just idling - same codes. I have not had it happen since.

 

 

Will let you guys know.

['84 Flat-Four]

It may or may not prove anything. But keep in mind, I did it once last week with the headlights on and I missed it. Thought everything was good to go. Wasn't till the real bad misfire and shutter that I started from square one again.

You really need the pitch black darkness and your eyes adjusted for night vision.

And don't worry you won't short or fry anything with the spray mist or shock yourself by doing so.

And its worth noting that my wires and coil tested within resistance spec before the spray test.

Edited January 23, 2010 by '84 Flat-Four

[Cougar]

If I remember correctly some others folks here have fixed a misfire problem by replacing the cam sensor and sometimes the O2 sensor.

[subynut]

Ah more data. Will check that sensor.

 

It was COLD this morning!

 

YES, That's SNOW in southern Arizona!

 

Well, I TRIED to swap the neutral switch, but the parts guy ordered the reverse light switch! So, I will have to wait some more and get the right part. One side note: the only difference between the two connectors is that the key for the connectors are on opposite sides and thier color.

I did drive it some more and it's definitely in the 3000-3500 range that will trigger the codes. I tried driving in 4th at 55mph which puts the rpms at ~3200 rpms and 30 seconds later....blink blink. Stopped and check the codes: misfires on 3&4 two counts each.

On another note, after I reset the computer, I went to start her back up to head for home and it acted like something broke - kinda like a "reer oof!".....odd... try again and alls happy.

 

I'll check the other sensors and the encoder wheels to see if there is something amiss. But for now, it's time to eat!

[pearlm30]

Jusrt a suggestion, IIRC, someone here cured the missing problem by adjusting the valve clearance.

Good luck

[subynut]

So, then the EJ25 is a solid lifter engine, I take it, yes? This is interesting.

 

Oh my, didn't realize the pics were THAT big. Gonna have to fix it. Much better.

 

One note about the neutral switch is that the old one definitely has a worn spot on the end of the sensor.

Edited January 24, 2010 by subynut

[doc526]

I did get to looking at the soob but, I did not pull my IAC this weekend.

 

As far as I know, it is not a solid lifter engine. From all the reading I have done, I am sure that it has hydraulic lifters. There should not be a need to adjust valve clearance once valve lash is set. I do see the possibility of failing lifters or valve springs that are getting weak.

 

Nice pics!

[subynut]

Well, turns out the neutral switch is a dealer item. I checked the electrical properties and they operate the same. So, I swapped the connectors. Went for a test drive and ....blink blink... 2 counts each - misfire 3 and misfire 4. Shows up over 2800 rpm. Only difference is that it drops the idle sooner and the drivability seems a little better. Still hiccups though. Strange thing, that switch was shot.

Well, on to more diagnosing.....

[Gloyale]

Firstly.

 

The DOHC EJ25 is MOST DEFINATELY a solid lifter motor, and it is possible you need to use a different adjusting shim for a few vavles.......not likely though.

 

BUt to the point.......

 

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.