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Old 07-16-2002, 10:41 PM   #1
Fish
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Default Signifigant loss of power durring light throttle

My car..
Intake, Catback, S-AFC, ITC.

the S-AFC and ITC have been zero'd for the time being with no effect to the condition.

Here's what is happening.
it happens under light throttle..
you can just feel the car lose power, to the point of bogging out.

if you press on the gas, it just bogs more... to the point of having NO power.

if I down shift and put the car in the higher range of the lower gear and apply some throttle it runs seemingly normal.

One observation when it happens, the A/F ratio gauge drops off the meter LEAN..

but I don't think it's just "leaning" out.. sumtin else is up.

timing belt?
ignition?
fuel starvation?

don't know..
thoughts?
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Old 07-16-2002, 10:45 PM   #2
Fish
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more info..

it's a 2000 with 73K on it..

regular oil changes, tho I'm falling a little behind on this one.


My father had the car today to look at it.. he noted that it seemed to get worse as the car warmed up.
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Old 07-16-2002, 10:46 PM   #3
Costas
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MAF
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Old 07-16-2002, 10:59 PM   #4
Poppa smurf
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oo+ would be MAP, have you checked the TPS on the S-AFC? does it read properly in percentage? might want to check the connetions again
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Old 07-17-2002, 01:37 AM   #5
tcs007
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I don't know what to tell you, Fishy, but my car did the exact same thing for 3 days straight, and it mysteriously disappeared.
Hasn't happened since, so I think it worked itself out.
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Old 07-17-2002, 01:46 AM   #6
Reciprocity
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Have you replaced the plugs? What about the spark plug wires? And the PCV valve?

From my experience with older cars...sounds like a tune-up type situation. First thing I would do would be replace the spark plug wires (if they haven't been) and replace the plugs (if they haven't been in a while). Pull the PCV valve and at the minimum clean it...or simply replace it. Cleaning is part of the 30K service, replacing (If I recall correctly) is at 90K.

Change the oil...car is always happy when you do it. Check the charge on the battery. Check the major power lines (positive and negative).

I wish I could say specifically what I think it is...but I haven't a clue. But a "major" tune up couldn't hurt...especially if you, like me, are a DIY kinda guy.

Other than that I'm stumped. The only other thing I could think of would be to use and OBD-II scanner and check the numbers out vs a same year car with similar mileage.

I HATE mystery car problems. They keep me up at night...

NC
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Old 07-17-2002, 01:52 AM   #7
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Try the SPG mod
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Old 07-17-2002, 01:58 AM   #8
Reciprocity
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Quote:
Originally posted by Kostamojen
Try the SPG mod
Yeah, I agree...couldn't hurt.

Isn't it past your bedtime Kost?



NC
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Old 07-17-2002, 02:00 AM   #9
Kostamojen
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Quote:
Originally posted by dcrawford
Isn't it past your bedtime Kost?



NC
How did you know my work schedule?
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Old 07-17-2002, 06:56 AM   #10
Fish
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SPG is the grounding mod.. correct?
worth a shot

I was talking to some other members and the 02 sensor was suggested to me as well.

so, I've got a list of little things I can do myself..

sounds good.
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Old 07-17-2002, 07:13 AM   #11
Patrick Olsen
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Can you describe a bit better how it feels, Fishy? Does it sound like my description http://forums.nasioc.com/forums/show...ght=hesitation might be happening to you?

I still haven't figured out why it's happening, but I have confirmed that the ECU is pulling timing, and then dumping it back in alluva sudden. (I just picked up a www.pocketlogger.com so I've been doing a wee bit of datalogging).

Pat Olsen
'97 Legacy 2.5GT sedan

PS - Try resetting the ECU. It's only a temporary fix, but it makes my car feel quite a bit better for a couple of days. I just reset mine last night, and I'm going to try to datalog over the next week or so how things change.
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Old 07-17-2002, 09:22 AM   #12
m750
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pat his description, I think, conensides w/ mine of hesitation at partial throttle, low rev's. I'm begining to think more and more it's an 02 sensor. I'll see if I can pull any codes from fishys and do some data logging tonight.
AO
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Old 07-17-2002, 09:25 AM   #13
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I cast my vote for a bad 1st O2 sensor if it is to the point of bogging. I had similar problems and it turned out the sensor was bad. My car would almost die under partial throttle, but since the ECU dose not go off the O2 sensor under WOT it ran fine when the pedal was to the floor.
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Old 07-17-2002, 09:40 AM   #14
Tim Smith
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You are burning extremely lean if you can't smell gas. That is why you are bogging.

Look at the things that tell the computer that more air is coming in. TPS, MAP or MAF, O2 (just fine tunes really though), ATS.
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Old 07-17-2002, 10:27 AM   #15
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I'll second the hesitation thing. I just changed my oil last weekend and since then, hesitation was horrible, car ran like shiat. It's like the car had a miss or just sputtered around 220-2500 rpm.....then would take off

I reset the ECU last night, ran it today to work, seems better. It will get better as days go on, and ECU learns stuff. It was runnin great before the blasted oil change.

Stupid knock sensor. I did do the knock sensor mod too.....so we'll see how that works out.

Josh
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Old 07-17-2002, 11:03 AM   #16
DanzBorin
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Along with the O2 sensor could be weather. How warm has it been up your way? You might have been having the problem (to a lesser extent), but didn't notice due to cooler weather, but now it is apparent due to warmer intake charge. Just a thought... Also try cleaning your filter... Can't hurt and could help. Hope you get it cleared up.
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Old 07-17-2002, 12:04 PM   #17
ciper
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Before reading all the responses the first thing I thought of was the TPS. It could be that a portion of the TPS is dead. Check the resistance and move the throttle back and forth, should be completly smooth.
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Old 07-17-2002, 12:31 PM   #18
paultg
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I was thinking the car was running lean, so it could be a part throttle fuel problem, like a bad fuel pressure regulator or a bad fuel filter.

Remember, if your going to replace anything, start of with the cheap stuff.

Paul G.
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Old 07-17-2002, 11:39 PM   #19
Fish
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yeah, I'm going to make plans to do the PCV valve.. the forward O2.. and an oil change.

I didn't have the car with me at Aaron's, so no code running/datalogging occured.

Pat:
the hesitation is rather smooth.. no real bucking.

I'm really hoping the O2 will do it.
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Old 07-18-2002, 12:34 PM   #20
ciper
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I dont see how an 02 sensor will make a difference. Ive heard of many ej22 running with no sensor at all just fine. Even the most rich or fail safe fuel ratio wouldnt make it as bad as you describe in my opinion.
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Old 07-18-2002, 12:58 PM   #21
m750
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ciper - I've heard otherwise...
the symptoms to me seem like partial throttle ( >20 <80 ) where the ecu is basing it's fuel on the 02, then at full throttle it's running on static maps which seem to be ok. Which to me, sound like classic 02 sensor problems.
AO
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Old 07-18-2002, 04:46 PM   #22
ciper
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Recently I was reading a web support board for ej22 based aircraft. Many were recomending removing the oxygen sensor and running the engine like this. I guess it may not be applicable since they only really care about the car at 5k rpm.

Its still easy and alot cheaper to check resistance values of the TPS. While your at it you might at as well check for proper function of the closed throttle postion switch. I set mine for .28 closed .29 open.
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Old 07-18-2002, 08:44 PM   #23
Kevin Thomas
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Default Solution

Spark Plugs, dirty throttle body, clogged fuel filter, timing problems, induction system leak (intake manifold, throttle body mating surface/gasket.....Any one of these.

I'd try the SPG mod and new spark plugs first. Then a new fuel filter....all for cheapness.
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Old 07-23-2002, 11:41 PM   #24
lil'greenimp_98
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Unhappy hesitation when jumping on it

ok this forum is unfriggin believable! just a wealth of support - screw honda and the acars! anyway heres my prblem:
i just rep'd my MAF sensor 2weeks ago and since then i have this hesitation problem: if i jump on the throttle (floor it from idle) like to merge or leave a stop the engine bogs and sputters for about a second then takes off like it always has. i reset my ecu when i put my new sensor on, and i have pulled my plugs and they look good - no burning or fouling...is this problem related to what you guys are discussing? is it possible my cat is causing this problem?and what is this SPG mod?
thanks for the help
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