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Old 04-17-2001, 06:03 AM   #1
KITTbri
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Angry high speed-high rpm power drain

okay... help here, around 90 - 100 mph the car is in 4th (AT) and about 3800 rpm
When I cross over to 4000 the revs flatten out and actually fall back about 200 rpm. I was going up a moderate grade and the engine would not accelerate. It stayed right at 4100 rpm. I even noticed it dip down a few times when it was around 4400-4500. I mean a SIGNIFICANT dip, about 3-400 rpm!

My question, is this the “flat spot” or is this the infamous ’99 knock sensor again? I don’t [notice] this I the lower gears, but then again the acceleration is greater in these gears…

Come on all you 99ers out there… help a brotha out!

-brian-
“struggles with performance issues”
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Old 04-17-2001, 06:45 AM   #2
ColinL
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I don't know about the "infamous" knock sensor problem, that was a DOHC thing and possibly confined to the US-produced models IMO. (yes, I've seen HobieGary's page.)

You could have the infamous 99 MAF problem though.
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Old 04-17-2001, 06:58 AM   #3
SoobyNewbie
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Unhappy

I don't know if this helps or not, but in my 2001 forester (also auto), I have the same thing happen to me going up a long grade at about 65mph in 3rd gear, around 4000rpm. It just levels out, and no matter how much I let-up and then stomp on the gas it won't accelerate or downshift again. Sometimes it will gradually drop back to 50-55mph, *then* downshift and accelerate back up. If I get a "running start", i.e., approach the hill over 70mph it can sustain 70-75mph with no problem. This is driving through the rockies at ~8000 feet so there's probably a lower "levelling" off point here.

The dealer said it's normal, that the engine just doesn't have enough power to accelerate all four wheels at that point... I told him my fiance's saturn (also auto, with way less hp) accelerates better than that up the same hills, and again he said it's because of the extra power needed for awd vs 2wd.

Sorry for the long post, but this is my main gripe about the car, and since I got it specifically because I thought it would be better suited to mountain driving, it's pretty annoying. Maybe someone's found a way around it...? (short of trading in for a 5-speed )
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Old 04-17-2001, 07:24 AM   #4
KITTbri
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ColinL – if was the MAF wouldn’t it affect me at all driving ranges? Not just high RPM?

Sooby – that dealer is full of crap, the car has 165hp, more than enough to pull up hill, have him run a diagnostic, even I know that is wrong. Your issue sounds similar to mine but if yours is a 00-01 you have a MAP and it shouldn’t be an issue.

I always understood the MAF problem to be at low RPMs and mostly with aftermarket CAIs. I have all stock intake save for a K&N drop in.
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Old 04-17-2001, 07:32 AM   #5
the Dabbler
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Don't know much about auto transmissions, but is this your lockup torque converter kicking in? I.e., it can't accelerate very hard at that speed/incline, so the load isn't changing, so the tranny thinks it's steady state and activates the lockup (thereby dropping the rpms by a couple-three hundred rpms)?

Re SoobyNewbie's observation -- 8000 ft is pretty high up. I wonder how many of those sea-level 165 horses are still breathing up there.
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Old 04-17-2001, 07:43 AM   #6
KITTbri
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Well I also ran on a level surface to see if it was the TC perhaps… it did the same thing but not as dramatically. It still retarded(?) around 4000-4500rpm. I didn’t have the length of road to push it higher to see if would pull once I got past 4600 – redline. I need to find a longer more deserted stretch to try this… I am thinking of eliminating the stock silencer and running 3” plastic piping down to the bumper vent to see if that will make a difference, but if it is the knock sensor that prolly won’t do a damned bit of difference.

This is so frustrating… sometimes it makes me contemplate selling the car for something more easily modded…
Then I have to remember how much money I would lose selling the car…
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Old 04-17-2001, 07:44 AM   #7
SoobyNewbie
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Thumbs down

Yeah, I've had them run the engine diagnostics 3 times so far, and they even reset the ECU for me last time... supposedly no error codes showed up, and they couldn't find anything abnormal. After the reset it was more responsive on fairly flat roads, but still lost power going up long hills.

They said if it keeps happening they could try to set me up an appointment with a subaru factory rep that comes around a few times a month. I might take them up on that offer!
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Old 04-17-2001, 07:47 AM   #8
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AutoBri, just saw your second post (same time as mine!) My car will pull almost to redline if on flats if I push it hard enough... especially after the ECU reset. When I can get it to downshift on hills it will do the same, but it's just really hard to make it downshift sometimes.
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Old 04-17-2001, 07:57 AM   #9
RugDoc2003
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i don't know if this will help... but i've had quite a few A/T honda accords that did this same thing... it was more noticable on roads with an incline on them...

maybe it is just a feature of the A/T that allows for slitghtly better power/acceleration at that RPM?
-rug
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Old 04-17-2001, 10:39 AM   #10
skidplatez
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AutoBri-

I KNOW exactly whats wrong! You bought an Automatic!
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Old 04-17-2001, 11:17 AM   #11
the Dabbler
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I guess what I'm saying is that it could be more of a design issue with the programming of the transmission as opposed to something broken per se.

Assuming the dip is sudden, like a shift, as opposed to gradually falling off, then it certainly sounds like the torque converter is going into lockup. Even on a level surface, the load may not be changing much at 100mph (thanks to our refrigerator-like aerodynamics).

As far as what to do about it -- have you looked into aftermarket TC's?

But again, I don't know much about automatic transmissions.
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Old 04-18-2001, 12:03 AM   #12
KITTbri
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Tom – you’re just jealous cause an AT gets better accel… um gas mileage. Yeah that’s it.

Dabbler, its not a hard drop off it is like the throttle is being dropped back even with the foot on the floor. It is a gradual decline followed by a very slow increase.

ANYONE experience this issue around 90-100?

-brian-
“can’t seem to keep it up there”
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Old 04-18-2001, 12:09 AM   #13
the Dabbler
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Quote:
Dabbler, its not a hard drop off it is like the throttle is being dropped back even with the foot on the floor. It is a gradual decline followed by a very slow increase.
So much for my TC lockup theory...
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Old 04-18-2001, 12:12 AM   #14
Blindeye_03
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In my 00 civic ex *auto tranny*, it would accelerate in 3rd up to 80 or 90 mph..cant remember where it ended, but when it engaged 4th (especially uphill) I could feel its power level off around 98mph (in 4th gear)...I think that in auto trannys the 4th gear is the overdrive gear...blah bllah i dont know where i am going with this ...HAHA...
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Old 04-18-2001, 08:07 AM   #15
SoobyNewbie
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On flat ground my forester will accelerate in 3rd up to 70 or 80, it's just on an uphill it peaks at about 60 or 65, and that's about it. No sudden drop-off, but no more power.

Like I said the dealer didn't seem to think there was anything wrong, but I see other subies whiz past me when I have it floored!

I ordered a GanzFlow last week, maybe that will help... but I really shouldn't need any mods just to make it up a hill at a decent speed
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Old 04-18-2001, 08:12 AM   #16
KITTbri
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okay you have serious issues then. my car will do 90 easy in 3rd on the floor. it will do 60 floored in 2nd. if you document enough they might give you a new one under lemon laws... does CO have those?

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Old 04-18-2001, 05:47 PM   #17
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I know I keep metioning my civic, but it was the last car I owned with an auto tranny...I personally think it is normal...I would be going up hill and be stuck at 67mph... I think the lack of torque made it do that + the gear ratios, b/c as soon as it went into 3rd or 4th it would just flatten out...

my $.04
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Old 04-18-2001, 06:02 PM   #18
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If you were doing close to 100mph in 4th gear AutoBri, it might have been the speed governor. I know that at least the 1999 RS has a limit of either 110 or 120 mph and it will cut out and the RPM will drop. If you have other than factory sized tires and wheels your speedometer may be reading slow. I read about the governor in the review in Car & Driver or Road & Track in their Hot Compact Car Shoot out issue. They were disapointed too, it hurt the RS in the comparison. I have a standard and about 110-115 mph is about the best I can crank out on a flat straight away before it just doesn't want to pull anymore.
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Old 04-19-2001, 06:22 AM   #19
KITTbri
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Everything is stock on my car ‘cept the drop-in filter. No sense in modding when stock it doesn’t run correctly, that would only exacerbate the problems.

Is there any way to disable the speed governor? I did notice that if floored all the way to redling in 3rd when it shifts 4th that the rpms are about 4400 and it pulls SLOWLY from that to about 110. I did not have any room to faster than that, had to back off. I think the governor lets you run higher, I have had the car to 115 before all this started. I still think this is an engine related issue. I plan on changing the fuel filter this weekend, the car has 28k miles on it, about time to change?
-brian-
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