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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

#1 Guest_rtp373_*

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Posted 09 June 2003 - 07:46 AM

I need to ask the question once again about this engine hesitation I encounter.

Only happens sometimes after restarting the engine and it's only been sitting around for a few minutes (so it's still at operating temp).

The dealer tested all of my sensors and found nothing, no errors in memory.

What will happen is there is a tiny little dead spot on the accelerator pedal and when you resume acceleration after coasting, the car does not transition smoothly, especially since I have the standard tranny. Probably if I had the automatic I would never feel this.

It goes away after the car's been driven for a few minutes, so it's nearly impossible for them to diagnose. AND it's not every time I restart it does this.

Others have reported the same issue. Ones who reported a bad O2 sensor saw a rapid decline in the car's operability. Mine, it's been a year since I bought it.

#2 Guest_Legacy777_*

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Posted 09 June 2003 - 04:29 PM

Does it only do it when cold, or right after startup?

#3 Guest_rtp373_*

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Posted 10 June 2003 - 04:44 AM

only when restarting a hot engine, but not every time you do. smooths out after 5+/- mins of driving. never has happened under any other conditions or circumstances.

#4 Guest_Legacy777_*

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Posted 10 June 2003 - 06:06 AM

Hmm.....unfortunately, you may just have to live with it. Have you been able to reproduce it for the dealer?

Have you tried resetting the ECU?

#5 Guest_rtp373_*

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Posted 10 June 2003 - 07:42 AM

Yeah, the ECU has been reset at the last 2 oil changes. No difference. Mechanic says he felt it was an inherent characteristic of the car and most likely nothing could be done about it.

The O2 sensor has been my only lead, but everyone else's failed miserably after a few weeks, and my engine runs like a top a year later.

Couple of people on my last string I started says their 2003 BAJA and an earlier model Forester did the same thing and wished they could get rid of it.

Getting a new clutch, anyway, so I have little to complain about; if I had the auto tranny I probably wouldn't even notice this.....

#6 Guest_Legacy777_*

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Posted 10 June 2003 - 03:20 PM

I'll take your manual tranny and you can have my auto.....how about that ;)

#7 Guest_rtp373_*

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Posted 11 June 2003 - 07:31 AM

Once I get the clutch replaced, I'll probably stop bitching about the fact that I didn't buy an automatic; I do remember vividly the increased amount of "punch" the manual provided. The power seemed to be lost in the auto somewhat.

Just harder with towing, etc.

I guess the hesitation is a inherent characteristic.

RTP373

#8 Guest_meep424_*

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Posted 11 June 2003 - 06:06 PM

I'm just gonna throw this one out here... TPS with a dirty resistance surface. Josh, you might have a better call on this?

Mike

#9 Guest_rtp373_*

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Posted 11 June 2003 - 07:56 PM

What does "TPS" stand for?

#10 Guest_scoobtech_*

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Posted 11 June 2003 - 08:53 PM

Throttle Position Sensor:cool:

#11 Guest_Legacy777_*

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Posted 12 June 2003 - 06:25 AM

tps I suppose could do this, but it's a brand new car.

Plus the fact it does it only after restarting the car and then goes away would not really make me believe it's the TPS......

#12 Guest_rtp373_*

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Posted 12 June 2003 - 07:42 AM

Josh, also I figure if the TPS was acting up the car would have a dead spot when I rev up the engine in neutral. Doesn't seem to have that. It's just going from coasting to accelerating. The only clue I have is knowing that the computer will shut the injectors off when the motor is back-driven by the wheels for pollution control and to help brake the wheels better. This is from a mechanic at the dealer.

So it's the response time under these conditions.

This is a toughie.

#13 Guest_Legacy777_*

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Posted 12 June 2003 - 12:18 PM

I don't think they'll shut the injectors off. They may decrease the duty cylce once engine load drops below a certain point. But I think most new cars would do this......don't know.....

#14 Guest_meep424_*

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Posted 12 June 2003 - 03:51 PM

EXCEPT that airflow during driving may keep the TPS at temps cooler than post-shutdown heat rising from the hot motor.

5 minutes would be enough for flowing atmosphere to bring it down a bit.

It's just a thought.

What happens if you progress more slowly with the accelerator? Still happens?

Mike

#15 Guest_rtp373_*

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Posted 13 June 2003 - 01:10 PM

oh, when it's doing this, pushing in on the accelerator a fraction of an inch, just barely touching it will get you no response and then suddenly it snaps to that level, causing a jerk. normally, if you do the same thing and it's not in this "mode", it is smooth as silk.

how much is a TPS?

#16 Guest_meep424_*

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Posted 13 June 2003 - 06:20 PM

Not cheap. dunno exactly. I'd definently want to test/clean before dishing out the $$.

Meep

#17 Guest_rtp373_*

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Posted 13 June 2003 - 08:17 PM

on another string, some guy said his new 2003 Baja was touchy like this, especially in low gear.

ah, I'll just keep an eye on it for now. my wife is like "what freakin hesitation are you talking about? Wha??!"

She finally noticed the clutch shudder 6mos after I started questioning it.

#18 Guest_meep424_*

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Posted 14 June 2003 - 05:52 PM

Hmmm.

These engines have alot of torque compared to other 4 bangers-- I suspect the long intake runners, characteristic of most boxers (unless dual carbs, etc) is the primary reason. Anyway-- it makes that first "kick" more noticable. Lots of folks here pick up on the more subtle things that many never notice. Maybe the wifey is right?

Mine always gets me when the A/C is on and I'm trying to inch forward in city traffic (5 spd). The pump goes on, car compensates w/ more gas, and that motor jumps me forward. Smooth, yea right...

Meep

#19 Guest_tcspeer_*

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Posted 14 June 2003 - 09:03 PM

Last T.P.S. I bought was 74.96 for a 97- 2.2 engine, but this was with postal discount, we get at Litha Subaru. First one I bought was 149.00 from dealer in Ft. Worth Tx. they only handles Kia's now. My car has had idleing problem's

#20 Guest_tcspeer_*

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Posted 14 June 2003 - 09:12 PM

I think I would ck.the air flow sensor or timing.

#21 Guest_remarcable_*

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Posted 14 June 2003 - 11:11 PM

Meep- I hear you on the AC issue:

My driveway opens onto a busy city street and on several occasions the AC compressor turning on has caused unintended acceleration strong enough to move the car over the curb into traffic unless I jab the brakes even harder. The first time it happened I was lucky enough to have my left foot on the brake already, and avoided being killed by the 18 wheeler which was passing by at the time.

It's scared the piss out of me on a number of occasions and I no longer turn on the AC unless I'm cruising.

#22 Guest_rtp373_*

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Posted 16 June 2003 - 07:40 AM

Is there a direct connection between a malfunctioning O2 sensor and the smell of rotten eggs/sulphur? I noticed this after getting out of my car this weekend....

#23 Guest_Legacy777_*

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Posted 16 June 2003 - 04:20 PM

Yes there is a direct connection.

If O2 sensor is not functioning properly, a/f ratio could/will be rich. A richer mixture burns faster and hotter, and also can leave more CO in the exhaust. This can cause the cat to possibly overheat and give you the rotten egg smell.

#24 Guest_rtp373_*

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Posted 16 June 2003 - 06:26 PM

I'll have them look at it when I get my clutch replaced - after I drive to Prince Edward Island and back.

I did verify there's a dealer in Charlottetown out on the island......

#25 Guest_rtp373_*

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Posted 17 June 2003 - 07:44 PM

Did a little test on the way home. Stopped after running the engine for 10 mins on the road. Shut off for a couple, started back up, ran fine, pulled over and shut off again for a minute or two, started back up and the hesitation was there.

Did the same thing last time after I went to the dealer - hung around town for a few minutes. By the time I had started the engine a fourth time, it started jerking slightly going from coast to accelerate (not smooth like it was) and returned to the garage. The mechanic told me to call the svc manager in the morning, and by the time I got back in the car, which was still running, it wasn't doing it.

When you shut off the engine, does some raw fuel get dragged in and could it possibly be fouling up the o2 sensor or a plug? If the car sits for 15 mins, it won't do this upon startup. If the car is run for 3-5 mins, it fades away and normalizes.

It's the act of shutting it off and restarting it moments later that makes it do it.




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