Idle surge

[PSIBRG]

Just wondering if anyone can help out with this. It only happens every now and then, and for what seems like no reason at all. I've noticed it seems to happen more when the car is warm, i.e. if I drive to the shops, shoot in for 15 minutes and come back out. I've had this problem with my Mirage (a few times actually), once I cleaned out the throttlebody and that fixed it, and once it was a faulty TPS. What's the common cause for this on Toyotas? Vid will explain a bit better than I can...

http://www.youtube.com/watch?v=S1joLP4JMwk

[FLAWLES]

check all vaccum hoses from behind the throttle body and the t/b its self

sounds liek an air leak to me

[PSIBRG]

Hmm I would've thought an air leak would have some affect on acceleration / make the car hesitate under load? Keep in mind it only does this occasionally, 90% of the time it's fine. You could be onto something though, will do the ole soapy water test and get back to you.

Anyone got any other ideas in the meantime?

[PSIBRG]

Ok, pretty much ruled out vac leaks.

I've gotta pull my throttle body off to replace my rocker cover gaskets, so i'll give it a good clean out and see if there's anything I can do about the idle control motor(?)... see how that goes.

[FLAWLES]

have you messed/touched the tps?

[PSIBRG]

Nah man, haven't touched the motor at all. TPS is sounding like a likely cause though..

It's happening more often now and it's kinda starting to piss me off, couldn't get it to stop doing it this evening.

It's kinda bad now. To the point where the car accelerates by itself uphill, and i've gotta sit on the brakes while cruising to prevent it from rapidly picking up speed. It's almost as if the car is stuck at 1/4 throttle or 2200rpm'ish, and the ECU is trying to bring the rpm down but the TPS won't allow it? Shit is that even possible? Either way it's really annoying, can feel the car squatting while sitting at traffic lights kinda like if you were sitting at the lights with one foot on the brake and one on the accel. Take my foot off the brake and it rockets forwards.

Heres another vid. I idle it for a while, then reverse while braking, then shift into Drive and let off the brake. No accelerator was used. Had to stop at 15kph cause it's on my driveway (slight uphill incline), but you can see how quickly it picks up speed with no accelerator input at all..

http://www.youtube.com/watch?v=V2WQSYjPk9k

Someone help please

[FLAWLES]

the only other thing i can think off and i am unsure if these engines have one is the idle control valve ( icv ) i have had a few play up on both 1jzgtes and 1uzfes

both had seized open

fix was to block it up

basicly to me with teh symptons you have stated

intenet diagnoses sucks dude take it to a mechinc

[PSIBRG]

Meh, I avoid mechanics at all costs if I can. Think of it as a chance to learn by doing/guessing

Anyway, picked up a throttle body from Looonie today, but didn't realise it was a traction control one. So instead of using it I pulled the TPS and ISCV off. Swapped the TPS over to mine, but my ISCV looked better so I just cleaned it up with brake cleaner and chucked it back in. Turns out the TPS was faulty afterall, was causing all kinds of havoc. The car drives fuckin beautiful now, doesn't feel like i'm neutral bombing anymore when selecting gears while stopped. Idles bang on 700rpm and stays there, don't have to floor the brake pedal to hold the car still while stopped, and doesn't accelerate by itself while cruising. Problem solved

[PSIBRG]

Ok, it's started doing this again. Started about a week ago with verrry minor symptoms and has gotten worse. Now idles at 2300rpm again and accelerates by itself. It breaks my heart driving it like this, feels so so bad for the car, so i'm gonna pull it off the road till I figure it out. Any help appreciated. Is there any chance the car is killing TPS's somehow? Anyone know where I might find a complete 2JZ-GE non traction control throttle body?

[PSIBRG]

So I went to start the car to go get lunch, and as soon as it fired it instantly revved over 4000rpm accompanied by the rattle of unlubricated engine parts I shut it off straight away. And started thinking. I didn't actually replace the ISCV last time, just cleaned the old one. So off came the throttle body again, and I replaced the ISCV with my spare one (which actually looks worse). Gave everything a clean again, reinstalled, reset the TPS. Fired her up, perfect.

Lets see if it lasts this time