Suggestions needed 96 Outback

[ocei77]

96 Outback with 2.5 and auto, 193K.

Symptoms.

Car bogs under load (incline) in D or 3. Manually shifting from 2-3 works.

Pressing hard on gas, car coughs and will not accelerate.

When holding brake in gear, idle sometimes fluctuates and dies, but not always.

Amazingly, sometimes I can go up an incline at very little throttle, at other times it dies.

Purchased at 186K, T belt and HG done at 146K by previous owner.

I have a 2.5 from a 98 Forester which threw a bearing for spare parts

What has been done so far:

I have replaced the plugs even though I did them 6k ago. They looked fine, but left the new ones in.

Swapped wires,CTS, IACV,MAF,purge solenoid, and EGR. All one at atime trying to see what if any effect it had.

NO codes.

Checked knock sensor, doesn't seem defective in any way, but the 98 has a different connector. Ordered a new unit and while I wait figured I'd ask what y'all think.

If not knock sensor, I'm leaning to a partially clogged cat or O2 sensor issues.

Thanks in advance.

 

O.

[3Pin]

Could be a fuel or exhaust issue?

 

take off the cat and see if it runs better.

[torxxx]

check fuel pressure. should be ~35psi

 

O2 sensors dont really cause the symptoms that you are having

[davebugs]

Just for kicks have the alternator checked. And the wires that go to it.

 

 

Any warning lights (not just CEL) like brake light and maybe ABS. Often these lights come on and the battery light doesn't. And you start to loose power at higher RPM as you drive since you're really running off of the battery. So it could have mpower when cold, fade after you've driven some distance, and battery recovers when you let it set a bit.

 

So it's worth a check of the alt. Weird as it sounds with no Battery light on.

 

All the other obvious thongs too from fuel filter to cat to flaky MAF. A bad knock sensor usually makes it sluggish especially when damp. And won't cause a CEL or a "pending".

[idosubaru]

You're sure the check engine light works?

 

I'd get some seafoam in the gas/intake in case there's heavy build up in and around the valves.

 

I once had a daily driver for my wife and I - 1997 Automatic 4EAT that would not downshift when the gas was floored, it would do the exact same thing on the same steep grades every time - 100% predictable...never downshift, i would have to manually downshift. Finally went away when I replaced the quarter sized filter in a vacuum tube hose on the passengers side. Goes from the intake manifold area to the passengers side fender well area in front of the strut tower. EGR solenoid related hoses I believe...but that's just a guess, this was 7 years ago. So either that filter/line was clogged or messing with those hoses did something.

 

Swap injectors?

 

Swap the ECU just for kicks...though it's nearly unheard of for Subaru ECU's to fail it does happen very rarely and they're easy to swap.

[Fairtax4me]

Kinda sounds like what my car is doing lately. Sometimes has a hard time moving out of its own way under 2500 rpm. Other times its fine. Power is good under light throttle, bogs down under heavy throttle. Very random though, never consistent.

Thought plugs and wires (plugs were overdue) but no change. Have had a long term CEL issue, has been on for 3+ years. Never had a real running problem until recently so kinda thinking my ECU is about to dirt nap.

 

Have swapped MAF, MAP, Knock sensor, ECT, fuel injectors, checked fuel pressure, compression a little low in one cylinder but still within FSM spec. Not sure what to think of it, if it were a continuous problem I would probably dig into it more but it's too random to know if its fixed for several days sometimes.

Edited December 3, 2012 by Fairtax4me
Spleling

[naru]

check fuel pressure. should be ~35psi

 

+1

Should have done it sooner.

[torxxx]

oh and btw the knock sensors are the same part from 95-2010+? the pin can be easily removed from the connector with a straight pick and you just swap the plastic connector.

 

But a knock sensor prolly isnt causing your issue either. It will throw a knock sensor code when/if its bad

[davebugs]

The little white connector I believe on some 95's were for lets say 1 wire and later for 2 wire. But you can probably change connectors as you suggest.

 

I've seen and replaced a few knock sensors - like a dozen or so and none of them caused a CEL. The car was just gutless compared to other Subaru's (be it a 2.2 or 2.5) and often the owner that sold to me didn't know why because there was no code.

 

It got to the point that if they were driveable I'd take the tools and a used kock sensor and stop for lunch, let the car cool, and install the used knock sensor to just get the car homw with power.

[ocei77]

Resolution. Prayerfully.

Didn't have a way to test fuel pressure w/o driving 40 mins one way to a friend's, but I did have a fuel pump assembly from the 97 L I had.

Installed and so far all is good.

Let the car go down to 5 mph going up an incline and it pulled steadily from there. No bucking, or anything.

Tomorrow will go out onto the roads here and see how it behaves.

Thanks to all for every suggestion.

Oddly Subaru's diagnostics had the fuel pump as the 10th and last possible cause of my issues.

All's well that ends well.

 

O.