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2007 2.5X L.L. BEAN
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150 Posts
Discussion Starter #1
Over the past month or so, my girlfriend has noticed an increased lag time between when she steps on the gas and when the engine actually picks up. This happens at any speed from dead stop, to pushing on the pedal to pass a car on the highway. When the car had 30k miles on it it was pretty responsive and had good get up and go. Now at close to 50k miles its a pig. She estimates about a 1 to maybe a 2 second delay between her pressing the pedal and the engine RPM increasing.
I'm not suere if its a throttle issue or something else, the car just has poor, sluggisa acceleration in any condition.
It has new plugs, and an air filter, and I cleaned the MAF sensor. We are currently running 93 octane, it was using 87 octane.

PLEASE HELP! THIS IS VERY FRUSTRATING.
 

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2001 S Premium
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228 Posts
just some ideas that can do this.

the cat might be going bad, it will kill power not sure about throttle response though

also the throttle position sensor might be going bad or needs to be adjusted. i dont know if you can on these cars but other makes can be rotated.

a knock sensor can go bad without throwing a code and severely retard timing causing no power whatsoever
 

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2001 S Premium
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228 Posts
other problems could be a lazy front 02 sensor and its on its way out. could be alot of different things. most likely knock 02 or cat.
 

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2007 Forester Sports XT 4EAT
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38,756 Posts
Really no need to run 93 octane in an X, but it's not going to hurt it. :wink:

Have you had a CEL? Long shot, but try a ECM reset, then see if the throttle response improves. If it corrects the problem, it may not last long, since the ECM will relearn & you'll be back to where you were. Still, it'll give you an idea of where the problem may be. :smile:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
 

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2004 Forester XT Premium 4EAT
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29,458 Posts
Could be a bad grounding connection, maybe? Two seconds to respond to throttle input is an awfully long time.
 

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2007 2.5X L.L. BEAN
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150 Posts
Discussion Starter #6
Thanks for the ideas so far all.
There is no Check Engine Light.
It likes 93 octane better, the engine runc quieter and gas mileage is slightly improved it seems.
An ECM reset is just pulling the + lead off the battery, how long should I let it sit with it off?
I hate to take it to a dealer, I just know i'm gonna get ripped, since I dont know how to test for bad sensors or have the equipment, theres probably no other choice .
I'd like to fix it though and I prefer DIY.
Alright, myabe 2 sec is a little drastic, although just a few days ago we were trying to make it through a light that was just about to turn red and she pushed the pedal and its like the engine did nothing for a second or two. and then all of a sudden it picks up like it should have in the first place.
 

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2007 Forester Sports XT 4EAT
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38,756 Posts
You're running a higher octane fuel than I run in my XT! IMO, if your Forester likes 93 octane better, that in itself could be indicating a problem. :confused:

ECM reset:
  • Lift off the negative battery cable.
  • Pump the brake pedal a few times to drain any residual power (operates the brake lights).
  • Reconnect the negative battery cable & you're done, other than resetting the clock & radio resets.
Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
 

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2007 2.5X L.L. BEAN
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150 Posts
Discussion Starter #9
Checked for codes and did a system check today with an Actron scanner and everything was ok, maybe I will switch back to 87 or 89 octane and run some seafoam through the thing. I'm stumped for now.
 

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2001 SOLD!
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1,413 Posts
I had a lurch like that. I made my own grounding kit and it went away.
 

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2007 2.5X L.L. BEAN
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150 Posts
Discussion Starter #11
I'm not well educated on grounding kits, what is the theory behind them, how do they work, and can you buy them as a complete kit and not have to make your own, If I had to I could I guess. I've heard of them and I'm willing to try anything. Right now the car is just disapointing to drive.
 

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2007 Forester Premium
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I had the same thing. Never figured it out but have adapted my driving to prevent any damage or atleast learned to manipulate the response I want. No codes or anything either, it is annoying. I'd like a diy too but can't find it yet, even the dealer said "that's just how a forester drives, it's not like it's a STI". I told him I know my car and this isn't right but thanks anyways. I dont think I had to pay so it was good with me. Good luck
 

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2007 2.5X L.L. BEAN
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150 Posts
Discussion Starter #13
I just sent Flex Innovations an email to see if they have a kit for the N/A Foz. Maybe I will try this. Subiciv, I was lucky that a friend at work had a code scanner in his car, he let me borrow it, I was afraid of taking it to the dealer, even though it's under warranty, and getting taken for a ride by them. My local dealer does not have the most personable, or customer service oriented people working there. Bobby, thanks for the info on the ECM reset I had it backward, I will try this too.
 

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1999 Forester L
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128 Posts
Who is your dealer? I've had very good experiences with Day Apollo Subaru/VW out in Moon Twp(on what used to be Beer School Rd). Actually bought a new Subaru from them even though the other Day Subaru on West Liberty Ave was much closer, just because of the difference in the people's attitudes.
 

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2007 Forester Sports XT 4EAT
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38,756 Posts
Before investing in a grounding kit, I'd recommend checking all the ground connections. Check for a corrosion & tightness of the ground connections. If you find corrosion or even if you don't, clean the connection, coat with dielectric grease & tighten everything back up. :wink:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]
 

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My07 FXT
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288 Posts
maybe i missed it in the threads but has there been any mention of cleaning the throttle body? at 50K miles it can get a bit dirty. perhaps you can try having that cleaned. hope you solve the problem.

btw, not the best solution but you can install a Pivot 3Drive for better throttle response.......ttp://pivotjp.com/product/frame-3-drive-e.html...........I'm assuming your throttle's a e-throttle. this product amplifies the throttle signal.

i'd had one on mine for 3 years and enjoy the oomph and quick throttle response. just make sure you get the right harness.
 

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2007 2.5X L.L. BEAN
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150 Posts
Discussion Starter #17
The dealer closest to me is Bud Bayer Subaru in Washington PA. When I was looking at foresters in the beginning, I didn't deal with them after my first 15 minute visit there due to the bad impression from the sales person. I called them a few weeks ago to order some parts for my forester that I baught from John Howard Motors in WV, The parts guy didn't feel like helping me, so I called Jackie at Anapolis and was more than happy with her service.
I have a can of Throttle body cleaner, maybe I will pull the throttle body off and clean it up. Afterall I clean the MAF and the filter, why not the throttle body too. I just havent done it because it seems like the safest way to do it is to take it completely off.
Highlifter, thanks for the link I dont know that I will use this, but its an interesting option I've never herd of, afterall subaru DBW isnt known for the most snappy response.
Bobby, I'll check my connections before spending money, good advice, you never know.

Stay tuned I will let you all know if, cleaning the throttle body and the grounds helps at all.

Anyone remove the Throttle body before, anything in particualr I need to be watchful of when taking it off and putting it back on.
 

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2004 Forester
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46 Posts
My 04 FXT 5spd experiences lag and lurching when the ECM goes into limp mode. It seems to do this whenever I am forced to use 91 octane gas (which Subaru says should be fine). When I reset the ECM and use 94 octane the drivability is great! Changed the front O2 sensor without any luck. The diagnosis continues!
 
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