Jerking front to back?

[nrmskate]

When my car hasn't warmed up completely in the morning, it will act like someone keeps tapping the gas really hard then letting off, it does that rapidly as I look like a dumbass driving it down the street. So to avoid it, I have to give it full throttle. I changed the Engine Temp. sensor a while ago and the ECU is pulling no codes.

It does this until the car is warmed up.

Has anyone experienced this? Or have any ideas on what to do?

Thanks.

If need be I can try and get a video.

Video up: http://www.youtube.com/watch?v=X3ELh4GyK2E

[st280]

Umm, just let the car warm up? I'm pretty sure you should let ANY car have an initial warm up period.

[nrmskate]

That's not the point. The point is, that even when it's not completely warmed up, it should'nt be vigorously jerking front to back, it's not normal.

[shmit001]

Try cleaning your throttle body and make sure your IAC isn't stuck closed, or clogged.

[lflkajfj12123]

funny thread title is funny

[zenki.life]

Umm, just let the car warm up? I'm pretty sure you should let ANY car have an initial warm up period.

i hate when people make comments like this ^^^. funny title thats why i entered haha

[dori_sil8t]

what motor?

[SidewayZ-s14]

My SR does that.
I'm pretty sure all SR's have that "cold" start issue.

[nrmskate]

Ill give a little more info.

It's a SOHC, (KAE) Cleaned and new gasket on the IACV, seafoamed, and I ran some throttle/intake cleaner through the throttle body.

[drftwerks]

i like the jerk to have a little twist in the mix as well.

[nrmskate]

Okay, can we please get off the nasty part and on to fixing this problem.

No one has any clue? I think it could possibly be a hotspot on the clutch?

[Bigsyke]

Its your transmission input shaft or a warn bearing in your transmission. Mine does that too, but not as bad. I bet it only does that in 1st-3rd?

[shmit001]

Does it do this at idle or only in gear? Does the engine "search" at idle? There could be a dead spot in your TPS. Try that next. Theres 3 wires coming from it: reference voltage (5volts), ground and signal. Hook a multimeter (labscope would be better) to signal and ground (any ground to make it easier, do it with key on engine off). At throttle closed, signal should read anywhere from .5-.7 volts. Very slowly open the throttle (secure the leads or have a buddy do it since you don't have 3 arms) and sweep from closed to wide open. Voltage should slowly climb up to 4.5 volts. If at anytime there is 0 volts, replace your TPS. Dead spots will tell the computer to stop sending fuel, and you'll have bogs or lurches.

[wow-thats-a-cool-car]

are you knew to driving manual? try poping the clutch slower.

[shmit001]

lol and he gets better when its warmed up.

[Bigsyke]

Was the car originally an auto? Could be impropper fluid in the gearbox.

[nrmskate]

Ive been driving a stick ever since I was 13, I know what im doing lol.

And it's an original 5spd.

One thing that might be vital is, I accidently adjusted the Idle Screw to set my idle at 750rpms without unplugging the TPS, because at idle, it sometimes hops around. I think it's because of me not unplugging the TPS when I adjusted it, anyone know how to fix that?

[shmit001]

How come you wanted to change your idle? Where you having idling problems before hand?

[nrmskate]

I had swapped in a new motor, and the timing and throttle cable were tampered with by the previous owner, when we got it started it was idling at about 1000rpm and it needed to be 750rpms (KA24E Default)

[shmit001]

Turn your Idle screw back out, or in whichever. Let it idle at 1000. If the problem goes away, then you have OTHER issues that are making it idle high. Generally, you should never touch the idle screw. There will some other reason why its not idling properly, adjusting the screw is just an attempt to cover it up.

[supreme_1]

it most likely has something to do with your trans. do you hear it bogging or sounding like it wants to jerk in neutral?

i had the same problem with my nissan hardbody. there was oil leaking on the clutch and untill it was burned off it would do this. i did the same thing you did, blast it WOT to start off, or just ride the clutch, then after maybe 45 seconds to a minute of driving it would go away. it didnt show any signs of slipping or nothing once warmed up.

[Psycho 240 Freak]

Could be that your spark plug's heat range is too cold for your engine set up. I had this issue too when switching to a colder plug so I could run high boost.

[kevmeistah21]

can you please record it going down the street, i think that will crack me up.. i have that with my sr but not as bad..

[nrmskate]

Im not even going to lie, I look like a straight dumbass going down the road.

And the main reason the timing/idle was off and I had to adjust it, was because the previous owner was KA24E-T, so he had to retard the timing and adjust the idle screw.

[aziankingz]

is it like when you hit a bump while in 1st gear and your car jerks like crazy? that is the most annoying shit..

[nrmskate]

yes, and I got a video today of me inside the car, ill try and get one out of the car.

The jerking was so bad I about dropped the camera and I think I need a neck brace.

This shit needs to be solved ASAP, mechanics couldn't even figure it out.

If I just unplug the TPS then plug it back it, will that make it so it's reset to my 750rpm idle?

OR do I have to turn it back to 1000rpm and then unplug it and set it back to 750rpms?

[nrmskate]

Bump. Video coming tonight.

[nrmskate]

Heres to video.

Its almost done processing.

http://www.youtube.com/watch?v=X3ELh4GyK2E

[Bigsyke]

thanks for posting the vid.

Thats some sort of a trans issue. Im having something similar, however not nearly as bad. Mine does it mostly 1st - 3rd gears. My input shaft has some play. Almost sounds like the flywheel is warped. Its something with your;

clutch
flywheel
inputshaft/bearings
pressure plate
tranny fluid.

Nothing to do with your idle/engine.

However your idle issue could be something totally different.

[Addicted2Kouki]

YouTube - New Boyz - You're A Jerk (http://www.youtube.com/watch?v=c-PslGS6IlE)

?


LOL

[nrmskate]

I know it may seem like its not something with the engine.

But, idk, I have this gut feeling it is. Because, when it warms up, it's perfectly fine.

It will jerk like this through all gears if I don't let it sit for 15 min to warm up.

[lazysk8er2]

my e30 does the same thing but i dunno what it is i just let it warm up to operating temp before i drive. yours def seems like it could be a sensor. something isnt letting you get the right amount of mixture air and fuel or spark. could it be an o2 sensor? cuz before warm up its in close loop then it goes open. or vice versa i can never remember

[Bigsyke]

Its your gearbox/clutch, its not your engine. Even cutting your injectors wouldnt cause your car to jerk forward like that.

Get some amsoil MTG for starters.

[artdrifter]

hahahah my SR did this and i looked and sounded stooopid in the college parking lot. Cleaned the throttle body and ran some sea foam and i was good

[lovely10]

wow this happens to me too! except its when im in gear, not shifting gears...oh and my maf is unplugged

[joshchewuhh]

hahaha thought this thread was something completly different.


rofl

[nrmskate]

This does it when it's in gear to. Not when I shift into gear.

Ill will be going 45mph and it will start to jerk, just not as bad as the lower gears.

[lazysk8er2]

check the maf

[nrmskate]

I thought the MAF could be it to, so I bought another one.

Nothing.

I didn't think that would be it anyway, because again, it's fine when it's warmed up.

But this problem is still really fuking annoying.

[GaMBiTx]

Im not even going to lie, I look like a straight dumbass going down the road.

And the main reason the timing/idle was off and I had to adjust it, was because the previous owner was KA24E-T, so he had to retard the timing and adjust the idle screw.

+1, i agree, cuz i look like that too... i have the same issue , Ka24e as well.

[nrmskate]

Man, if someone solved this, they would be helping so many people.

Seems liek a lot of people are having this problem.

[ZX88]

my car does that occasionally when im in first in a parking lot and i take my foot of thegas and put it back on. Sr by the way.

[Bigsyke]

so like ive said before, if it was an engine issue it would be doing this OUT of gear. The OP puts the car in gear and the problem happens, thus like ive said;

1st Change fluid to amsoil MTG
Check CMC, Slave cylinder
Clutch release bearing, pilot bearing
Clutch/pressureplate,flywheel.
Input shaft/bearing.

I dont have a vss, 5th gear or nuet. position sensor and my car runs no different.

[nrmskate]

Well, the only thing I can think of, is the clutch, but would it do that until the car warmed up?

My clutch pedal is a little loose and the clutch slips a little bit.

When I ran the car for 10-15 min and shut it off, and then come back 10 min later, it's still warm so it doesn't jerk. But if I leave it off for 30+ min, it will jerk untiled warmed up.

[jmac636]

Have you checked for codes on ecu? It's not tranny related.
Here are a few things I would check first.

Properly set the timing

replace temp sensor on intake (not the gauge temp sender)

Maf wiring

Grounds-I would add some grounds as well cause 240's have always had grounding issues.

Harness grounding on pulleys- Ive seen this happen but will eventually blow a fuse.

Pull apart and clean all connectors using brake cleaner or carb cleaner.

check for vaccum leaks in intake by using th smoke method.

[nrmskate]

No ECU codes.

Brand new temp sensor.

Checked MAF grounds and voltage, along with TPS Voltage.

Im gonna try seafoaming it and seeing if that helps at all.

Atleast im not the only one that doesn't seem like it's the transmission.

[BKangS14]

Have you figured this out yet..my car did something like this and i would check your maf sensor connector and coolent temp connectors and anything around it