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Guest Message by DevFuse

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Engine Hesitation on 2002 OBW

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34 replies to this topic

#26 Guest_Legacy777_*

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Posted 18 June 2003 - 06:11 AM

possibly a leaky injector. It could be a number of things.

#27 Guest_Legacy777_*

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Posted 18 June 2003 - 06:12 AM

my suggestion would be to reproduce it with either the service manager or tech in the car, so they see what you are talking about, and then let them try and deal with it.

#28 Guest_rtp373_*

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Posted 18 June 2003 - 07:48 AM

will do that.

#29 Guest_rtp373_*

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Posted 28 June 2003 - 12:34 PM

All the way from Maine (Subaru Country) to Prince Edward Island, Canada - nearly 1000 mi round trip incl mileage on the island and didn't have any problems except for once, which lead me to a conclusion.

Josh, you commented in a thread regarding someone adjusting the TPS and how the computer resets idle position every time you start or restart the car (thus adjusting its position does little as long as it's within some set range) -

The one time I had a dead spot in the throttle was when I took off quickly from our cottage. You'd touch the throttle a bit and nothing then all of a sudden JERK forward.

I think what I'm doing is in some cases, I start the car in gear and the minute I release the key, I let the clutch out and take off, and the motor never reaches idle. Theory is it's setting the idle position while the throttle is slightly depressed.

When I got to the end of the access road and let it idle for a couple of seconds, from there on it was fine.

In all cases where I started, restarted, etc, I didn't launch the car immediately and I never had a problem other than that one instance when I did launch it.

Think this theory would stick? It does explain each instance where I experienced this problem.

PS, thanks for all the suggestions.

#30 kehunter


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Posted 25 September 2003 - 11:55 AM

I bought a 2003 Baja about a month ago. It was a demo, got a really good deal on it. When I road tested the car, it drove fine. When I brought it home, I noticed the bucking when driving between 30-40 mph and trying to accel or decel (mostly happens when accelling after coasting). Took it back to the dealer and the service dept. said it's the design of the car and that they hooked the transmission up to their computer and everything was running within specs. Service said if it happens again, to bring it back and they'll reset the computer (I assume that's what the ECU is?). Took it back the other day and had it reset, the service guy said that his Outback does it too, but I don't know if this is normal. Only drove it once since the computer was reset and couldn't get it to happen even when trying, so I'll have to see how it works out when driving it again. The service guy said it was possible that since it was a demo, the person driving it might have been doing all city driving and it "learned" to the way that person drove. I do mostly highway driving and he said that could be the problem. I see some people saying that they've had to reset the ECU multiple times to remedy this? It seems crazy that these cars can't accel or decel smoothly without tampering with the ECU.
Any comments?

#31 forester2002s


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Posted 30 September 2003 - 11:41 AM

My 2002 Forester (MT) hesitates when I drive on or off the car-ferry.

Typically, the engine is warm when I line up for the ferry. After a 15-30 minute wait, the ferry arrives and I restart the engine to drive aboard at slow speed.

The car lurches/hesitates in 1st gear, most notably when I ease off or on the throttle. Sometimes the hesitation is so bad that I deal with it by coasting with the clutch depressed in 2nd gear, and just give a little forward acceleration every few seconds to keep the speed up.

The same hesitation happens when I drive off the ferry, after a 30-minute sailing with the engine off.

This is usually the only time that I have noticed the hesitation. Although once, on a long journey, with the engine behaving flawlessly, I stopped in a rest area for about 3 minutes and then immediately resumed my journey. The hesitation was there at high speeds, when I eased off the throttle; it felt like a loose CV-joint! After I stopped for gas many miles later, the hesitation disappeared.

After reading previous posts, I wonder if I need to reset the ECU?

#32 rtp373


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Posted 20 February 2005 - 01:40 PM

I neglected to follow up on this thread...

The hesitation issue went away. I'm 99% sure it's because when I start the engine I let it come back down to an idle before taking off. Those times I had problems I would touch the gas and let out the clutch as soon as the engine fired up, usually after it was warmed up.

I learned that the computer recalibrates the "idle" position of the throttle via the position sensor every time you restart the car. I believe I was interrupting this process by taking off without giving it a "second" and my throttle position was zeroed "above" the real setpoint later on.

What would happen is there would be a dead spot until I had rotated the throttle body into what the computer was the position just above idle and as a result the engine would jump or delay accelerating.

Just a theory, but haven't had ANY issues since I just backed off and let her idle a quick second.


#33 mikem


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Posted 20 February 2005 - 05:11 PM

I went thru similar problems with my 04 3.0 H6. Left no codes when it had one of its spastic fits. Finally found a dealer in Raliegh and a technican that had some knowledge of the problem. A faulty TPS with dead spots in it was causing the bucking and poor running. My dealer was open to the idea that they could not fix it and called the other dealer for info. Replaced the TPS and cured all problems. The straw that broke the camels back was the throttle would stick at whatever position it had when the fault would occur. I filed a report with the National Highway Transportation Safety Administration and walked that into the dealer also. I think the Explorer/Firestone tire episode has made them a little more sensitive to early warning signs that the public may actually have brains.

#34 rtp373


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Posted 20 February 2005 - 08:10 PM

Wow, that's pretty scary... I'm glad my issue was resolved with a behavior change.

I've never had that problem again once I gave it a second to set in.


#35 forester2002s


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Posted 10 May 2005 - 12:19 PM

Yes, this really works on my 2002 Forester:

- Start up, and drive off immediately: Causes engine hesitation and surging.

- Start up, idle for a few seconds then drive off: No hesitation, car behaves properly.

I have been testing this out for the last few weeks, and it seems to be the answer to my hesitation problems. I use a car ferry every day, and they ask drivers not to idle their engines on the ferry; so I always used to start-up at the last possible moment, and drive off immediately. WRONG thing to do in a Subaru!

Try it, you'll like it!

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