Jerking Back and forth.... help?

[zamorush]

Well, something happened. Not sure what and not sure how, and of course why....

It was a rainy day. Pooring down the freeway like from the bucket. Me and my bro head out to yet another surf trip.

The problem began about 10 minutes of driving on the freeway. At about 80mph, the car suddently began jerking back and forth, like it was about to die. I had to slow down to 60, and it stopped then.

The second time it happened when i was going up the hill, at about 60mph. Same day. All it was doing is jerking back and forth. The RPM's did not change at all, however Check Engine light was blinking.

I have no idea what it was. However, when i came home and checked the Check Engine codes, they turned out to be 33, and 52. (don't remember for sure need to look them up again). It turned out to be oxygen sensor, and fuel mix sensor. (again, not totally sure, need to look up when come home)

So if anyone had this problem, would you like to share? Thanks.

nik

[NikFu S.]

i have no clue. you say the rpms didnt change? if engine speed is constant i dont see how it could be the fuel. you might want to physically look around the engine bay to see if anything is loose as well as listening for clunking sounds. check for metal shards in your fluids.

yeah experience the same at the moment

like if i go up the hill and revs are under 2100 and its on the limit of the gear (60kmh or 90kmh for 3rd and 4th i think) I got the same,
feels like it misses combustion for quarter of the second and same jerking

well for me it seems to be the PCV valve and hose im missing
but for u it should be something else
(as ur revs are around 3500 when it happens)
(but not a bad idea to check PCV system and vacuum hoses look for link about PCV (recent))

but i think its more the petrol system problem as speed was high...

if it turned to be code 32 or 33 it does not mean at all ur oxygen sensor is dead, as i had code 32 4 months ago, when i had ATF all over it, and had code 32 for few weeks then it disappeared and never came back..

so dont hurry wasting ur money yet make sure first then do something

cheers
Sergi

[zamorush]

like if i go up the hill and revs are under 2100 and its on the limit of the gear (60kmh or 90kmh for 3rd and 4th i think) I got the same,
feels like it misses combustion for quarter of the second and same jerking

Yep, that is exactly what i had. Mine was at about 2500RPM, however, i haven't experienced this problem since.

I will see if it appeares again or not, then will think on what should i do next.

Thanks for your help Sergi.

P.S. btw, my codes are not clearing, i've tryed so many times, they are still there, weird.

what do u mean not clearing?

there is a way to do it described in how to section under ECU codes i think or soemthing like that

also try to disconnect the battery for a while, say like half an hour... could help...

physically check the O2 sensor... u could get some leak of oil on it or something...




wounder if take the signal from proper O2 sensor and wire it to both O2 sensor... mite save the buying of new O2 sensor.. as
SVX got one on each side and i think there should not be much difference in signal anyway...
thats just the way i repair cars lols wont advise to others tho

[zamorush]

I meant what i said, it is just not clearing. I've read all the procidures, i've done everything there is to do. My dad is an automechanic, even he could not do anything. Next step would be disconnecting the battery, and then if that won't help............. I am going to go and hurt my car (just kidding).

Well, anyway, today i have a long trip, so if i won't notice anything, then it is fine, however, if the problems go back again...... i'll start over.

nik

[mbtoloczko]

If the problem goes away under full throttle conditions, then one or both of the O2 sensors may be bad. (The O2 sensors are not used under full throttle conditions.) If the problem persists at full throttle, then I suggest having the MAF sensor tested.

ok ur jerking happens when ur car is under load but ur revs are relatively low for the speed...
like example u drive on 3rd at low speed where its more likely to have 2nd or car is on overdrive where its more suitable to have overdrive off.... well it s what for me...


but again i got crap idle so i think they both related as started bout same time....


well physically check O2 sensor.... i remember that mine did not want to clear too but then just did

i was getting check engine after 10-20 minutes of drive for 20-30 seconds or something like that for a whole month...
then everything just became to be ok... so i guess give it some time but start looking for the root of evil
neva replace things unless u r sure they cause problems
well unless u r rich

[zamorush]

Thanks guys! I will do as you say......... however so far the problem did not come up, so i guess i will wait. I still think it might be somehow related to the rainy weather, not sure how though.

nik

[Phast SVX]

Originally posted by mbtoloczko
If the problem goes away under full throttle conditions, then one or both of the O2 sensors may be bad. (The O2 sensors are not used under full throttle conditions.) If the problem persists at full throttle, then I suggest having the MAF sensor tested.

do you mean it just goes to preset fuel maps at WOT? Becuase the only time the 02's give an accurate readout via a a/f guage is at Wide opne throttle, the voltage jumps around the rest of the time....
phil

[mbtoloczko]

Originally posted by Phast SVX

do you mean it just goes to preset fuel maps at WOT? Becuase the only time the 02's give an accurate readout via a a/f guage is at Wide opne throttle, the voltage jumps around the rest of the time....
phil

At >25% throttle, the car feeds fuel based on the built-in maps and no longer uses the O2 sensors to trim the fuel feed. So, if there is a problem with the O2 sensors, it would not affect how the car runs at >25% throttle.

The stock O2 sensors are only accurate around stoich, and typically cars are jetted rich at large throttle positions, so the stock O2 sensors are useless at WOT.

I wouldn't really say the voltage is jumping around at <25% throttle. The voltage fluctuations representative of real changes in a/f ratio. The ecu is constantly leaning out and then richening the fuel mix based on the readings it gets from the O2 sensor.

so does that mean that if the throttle is less then 25%
and it s got problems with idle plus when car goes under load with low rpms and jerks thats most likely O2 sensor?

or it does not mean anything?

coz logically many things change with throttle more then 25%
like rpms go up more then 2000...

[mbtoloczko]

If the problems exist at only less than 25%, then there is a chance its the O2 sensor.