idling high 2k, 5sfe mt Options

[ILoveMySilly97]

The idle is fine all the time except when i drive it over 2k rpm. Then when i press clutch the rpm goes down to 2k and idles. The only way i can get it to normal again is to rev up to 2500rpm. Then it drops to 800. I'm thinking the diaphragm might be bad? This happens once in a while. One day it happens next day it'll be fine. A week later it does it again it sometimes a couple days later. Please don't say to clean tb.

1997 ST204
5SFE @ 212k miles
S54
2.75" CAI
2.25" catback-decatted

[Box]

Have you ever cleaned the IACV? What I'd do is do a quick check for vacuum leaks, with the car running spray some carb cleaner around the intake and throttle body and around any vacuum lines. If you can get it to get stuck at the 2,000 rpm while sitting then if it is a leak it'll be easier to find. Anyhow, if it starts to bog you've found the source of your problem. Another thing is to reset the ECU and drive it around for awhile and see if that solves it if it isn't a leak or the IACV. I had a similar issue where it'd get stuck at 1,400 or so and after resetting the ECU and driving it around it fixed itself. I looked for leaks etc... like a mad person to never find anything.

[VavAlephVav]

I thought I had mine figured out after I cleaned the idle speed control valve and calibrated the throttle position sensor, but a week later its acting funny again it just wants to idle anywhere from 1200 to 1700 unless I give the throttle a little bump then it comes back down.
does it sometimes, and sometimes not. I wonder if maybe the cts is bad. the iscv is clean, and the valve turns freely and the coil ohms out like it should and its air-tight. unless maybe you can adjust that bi-metal spring on the back of the iscv

[ILoveMySilly97]

^yeap exact same problem as mine. I know it's not a dirty/clogged tb or iacv as I already cleaned them last year. So I'm kind of lost to what's the issue.

[SAHEcelica]

i had the same problem in mine, a 94 gt. im not sure what stopped it, but i bought a new accelerator cable, took the old one out, installed the new one, the new one was defective and was stuck (not allowing the cable to freely move and get stuck, REALLY not good, and a scary ride that almost ended the celica), took the new one back out, installed the old one back, and it hasnt done it since.

my best guess is that the cable would get a little stuck (on maybe a burr or something) and flicking the gas pedal would "unhinge" the stuck part and let it go back to where it was suposed to be. from me taking it out and then eventually reinstalling it, i think smoothed it out a little.

with way, maybe worth messing with/lubricating/replacing the accelerator cable.

[VavAlephVav]

I have noticed that mine acts a little funny if I mess with the cable. it's all looped around the rocker cover in a full 180, I'm not sure how it is supposed to be set up in the first place I always thought the cable wasn't supposed to loop around like that.

[Special_Edy]

Its supposed to clip to the airbox, then run over the front of the valve cover and clip above the alternator, then it makes a 180 degree curve, clips to the intake manifold, and finally ends at the throttle body. Its a full 270 degree loop and its normal. The cable shkuld be adjusted so there is a small amount of slack, otherwise the throttle will be pulled open when the motor torques.

If you think about it its a Japanese car, therefore in japan it would be RHD, which means the cable would only have a 90 degree bend. In LHD models you would need a 270 degree bend.

This post has been edited by Special_Edy: Aug 3, 2014 - 3:54 PM

[VavAlephVav]

another thing I've been thinking about this problem, because ive seen Dozens of posts here and other places of people with the same problem. Maybe it's just the accelerator cable itself has just gotten dry enough that it wont release fully on its own until you goose it a bit. because of the way it has to loop back around 270 degrees of a circle and it hangs up a bit.
also mine is not "mounted" in place like it ought to be, I had always thought the guy who put the last motor in just half-assed it, but part of it is just the way the cable runs like Eddy is saying. so maybe if we take the cable loose so that you can straighten it out and get some Teflon lube down it or something it might return back to idle on its own.
which is pretty much exactly what SAHEcelica was saying

This post has been edited by VavAlephVav: Aug 12, 2014 - 9:58 PM