1994 Subaru Legacy Low Power on accelleration

Tiny
CAPTRON
  • MEMBER
  • 1994 SUBARU LEGACY
Engine Performance problem
1994 Subaru Legacy 4 cyl All Wheel Drive Automatic 80k miles

Situation: From a standing start the car is almost dangerous to accelerate smoothly into traffic from a stop, as you don’t know if it will simply and slowly pull out or pull out quasi-“normally". Sometimes it works well but not as a rule, you just never know and can never rely on it. Typically it is simply gutless and ranges from non to marginal acceleration. It seems to be slightly better when hot.

Then after driving another identically set up same model/year car, the difference was Gy-normous. I now realize its not just the Legacy 2L twin turbo as I have been told.

This has several Subaru Mechanics saying it’s inherent with the Subaru Legacy S/W 2L Twin Turbo. After asking around I found many Subaru mechanics agree but no-one has actually been able to track the issue down; several have tried. There are no codes.

I found a former Subaru dealer mechanic who admitted to trying to sort this problem before and that it’s pretty common. To that end he agreed to work on the car as an as-able basis. He also bought a donor-car that was working fine and exchanged out all the kit he could think of, including the turbo’s, computer etc to no avail. He has had the car now for 6 weeks and I’m trying to assist in some research to help.

I am not sure if it runs "˜normally’ on the highway as its always run like this, it seems to go "˜OK’ fuel mileage is poor as a rule 10-15MPG (U.S) and 20 on the Hwy, accelerates on the 2nd turbo OK for passing, but is a bitch on inclines without it, and occasionally the engine stutters drops to Get-home on hard acceleration (i.e. when passing!!). It could be unrelated

Stopping and turning off the ignition and back on again fixes this and it happen only rarely. Code indicates something in the turbo but nothing found.

Comment: I had a similar "˜89 single turbo 2L Auto legacy wagon before this one, and it was magic!

Getting very frustrated!


http://www.2carpros.com/forum/automotive_pictures/263563_TrademeDSCN1164_1.jpg

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Wednesday, October 29th, 2008 AT 4:58 PM

11 Replies

Tiny
JAMES W.
  • MEMBER
I'm not real familiar with the Subaru turbo system. But, going back to my experience with aftermarket turbo systems my first thought is the waste gate is stuck part way open or is opening too soon. Every one in the repair business knows what "turbo lag" is and it's an accepted fact. By your description, which is very good I might add, your turbo(s) aren't creating boost and actually creating an intake restriction. When this power loss condition exists, what does your boost gauge read.
After my stint with turbos I went to superchargers. They were more fun.
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Wednesday, October 29th, 2008 AT 7:41 PM
Tiny
CAPTRON
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"I'm not real familiar with the Subaru turbo system.. First thought is the waste gate is stuck part way open or is opening too soon."

Thanks for this thought, I will pass it on.

Yes I am familiar with turbo-lag, the old single turbo Legacy I mention had it, but off the line it was still more like a normally aspirated car on launch, that continued to gather through the RPM range, this car is gutless at its worse, you push down on the gas pedal and it only just barely accelerates at all, real dangerous in the wrong circumstance.

It doesn't run rough, splutter or anything other than low power, which does improve when the first turbo seems to spool up. From the point where you accelerate to the point where it starts to come on line it's more likely than not a real dog.

To be clear the car runs smoothly, has no oil use, and the engine is smooth through the RPM range once away from the low RPM's.

The waste gate could do that and be naughty enough to not be consistent, making not all launches a joke. My understanding is the Turbo and gate were changed out, and the vacuum lines inspected.

And to make things more complicated, the old system of a single turbo was superseded by the twin staggered turbo to allow a very small low RPM turbo to quickly spool up at the lower end, and later brings in the 2nd one around 4500rpm I think. You can feel it spool up when passing.

Thanks for your thoughts
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Wednesday, October 29th, 2008 AT 9:00 PM
Tiny
JAMES W.
  • MEMBER
I've said many times. If the engineers had to drive or repair some of this stuff, there would be some changes made.
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Monday, November 10th, 2008 AT 6:44 AM
Tiny
CAPTRON
  • MEMBER
There is no question that when new, these were the be-all and end-all for small wagons, the engine seems bullet proof, and for the most part the Subaru Legacy series is an awsome car/wagon.

BUT: i.E. Try changing the plugs! The idea of a coil for each plug is great when you have easy access to it. When it recessed into a head cover and then near impossible to get at short of jacking up the enginem some more thought to the serviceability would be nice. Granted the plugs now last 100k.

I realise the Dual Turbo system was not imported into the USA, but any help would be appreciated.
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Monday, November 10th, 2008 AT 2:08 PM
Tiny
JAMES W.
  • MEMBER
A question off the top of my head. Would it economically and financially feasable to convert the car to a single turbo system. Personally, I've always shyed away from deviating from OEM unless you plan to keep the car forever. Unless you make a drastic improvement, it always hurts your resale.
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Monday, November 10th, 2008 AT 6:33 PM
Tiny
CAPTRON
  • MEMBER
James, the car is factory Dual Turbo. Its just that the Dual Turbo option was not comonm in the USA, in fact I don't think they ever offered it there. In Japan and here though, its what they offer.

Cheers
Ron
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Tuesday, November 11th, 2008 AT 5:48 PM
Tiny
JAMES W.
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Just out of curiosity, where in the world do you call home? Your last posting made me wonder. Jim
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Tuesday, November 11th, 2008 AT 6:18 PM
Tiny
CAPTRON
  • MEMBER
We are based out of Auckland NZ, Jim.
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Tuesday, November 11th, 2008 AT 7:56 PM
Tiny
JAMES W.
  • MEMBER
COOL! I've always wanted to go there. I'm Minnesota, USA
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Tuesday, November 11th, 2008 AT 10:32 PM
Tiny
CAPTRON
  • MEMBER
;-)
We have been here about 13 years now and its as far a cry from Minnesota (Been there many times) as Alberta where we left -50c weather for the sublime weather of NZ. Its like stepping back 20 years in dome things and disposable dollars are low.

Here they drive on the "Wrong" side of the road not the "Right" side like the Japanese. Thus they import Jap cars as they are very expensive to keep after 50k km in Japan and here they are cheap and like new when they arrive here.

Hence we get the Japanese cars the drive in Japen, something difficult to drive on the Right.

Having said that I also have a Jeep Cherokee and a Ford Exploder (Explorer) all ex Japan.

We are now coming into Summer where it rarely gets over 29c (That's about 84degrees in the old F scale) and we saw 0c (32f) at 4am mid winter this year, although it got to 16c (60f) during the day.

Having said that: Gas (Petrol) was NZ$2:12/L until recently ( US$1.28/L and there are roughly 4L per US Gal.) Now it's down to NZ$1.60/L

It's a very neat place to visit and the US$ does go along way.

Stay warm, I will be thinking of oyu in Jan when I', in Melbourne Australia! ;-) Cheers

Ron
www. Eehnz. Com
digital self-heating homes
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Wednesday, November 12th, 2008 AT 3:04 PM
Tiny
JAMES W.
  • MEMBER
Ron, thanks for the little trip to the other side of the world. I'll be thinking of you when it's -25f here. Also, I need to respond to your posting or it keeps coming up on our answer board. Take care, Jim
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Thursday, November 13th, 2008 AT 1:22 PM

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