ISCV Cleaning (*May* solve poor/erratic idle)

[Sciflyer]

Not all ISCVs are serviceable in this way!

The one on my '94 1UZ is a completely sealed unit (see pic)

The plastic case is bonded to the aluminium, there are no screws and there is no way to get it off without destroying it (believe me, i tried)

also, looking from the open side the internals are different to the earlier (serviceable) 1uz valves

Just a word of caution

[ajh]

I cleaned the one on our 3S-FE after reading this thread sometime ago.

When I removed it I discovered it was so clogged with crap, the shaft wouldn't even move.

I actually soaked ours o/nite and cleaned it the following morning. ( I used carby cleaner)

The thing that prompted me to do it was the way the car was running with A/C on. Or should I say, nearly stalling.

Anyway, I'd checked everything else tied in with the A/C and all was normal.

I also gave the Throttle Body a good clean while it was off too.

Made the world of difference!!

[dave_g]

hi, my 20v is idles far too high, around 1750 -2000 rpm. When I clamp the hose on the iscv it idles normally at around 800 - 1000 rpm. would a clean fix this idle problem?

Thanks

[ViPeR_NiPPleX]

dave_g, check for codes from the check engine light. My dad found he forgot a power wire to his ISCV(or whatever equiv on blacktops) and it would idle high.

[dave_g]

dave_g, check for codes from the check engine light. My dad found he forgot a power wire to his ISCV(or whatever equiv on blacktops) and it would idle high.

Well, funny thing is, my o2 sensor is not plugged in as I do not have a full exhaust hooked up yet, and I checked the fault codes and it tells me everything is fine. Everything is not fine. Engine idles at 2000 rpm and it has next to no power.

Is there some kind of "safe" mode that the car switches to if it senses something major wrong? If so that would explain the lack of power output and maybe the idle problem too.

[ViPeR_NiPPleX]

it *might* go into limp home mode... it typically won't let you rev over 4krpm, and generally complains and splutters as you make it back to the garage.

[dave_g]

it *might* go into limp home mode... it typically won't let you rev over 4krpm, and generally complains and splutters as you make it back to the garage.

How do I get it out of limp home mode???? It doesn't have a speed sensor or an o2 sensor, might this be the reason it's in limp home mode?

Also, I managed to get the iscv off the engine and it's clean and works fine. High idle speed unresolved.

[EldarO]

take battery terminal off, and hold down the brake pedal to get any residual power out of the ecu, this should reset it.

Elmo.

[4agerolla]

I'll be trying this on teh 7M in the next few days... sometimes the idle drops veeeery low (<500rpm) to the point it nearly stalls, jab the go pedal and it jumps back up to normal smooth as a babys ass 7M idle (650ish rpm)

hopefully this fixes said problem! shall let the thread know!

Chris

[deeps]

I've had idle problems for quite a while now, and I think this is about the only thing I haven't tried. The problem seems to also be getting worse.

So i tried to get it out, but I simply can't get the hoses off the bottom part off! I always get stuck at stupid hurdles, like nuts/screws that refuse to budge, or hoses that won't come off etc.

Any tips/tricks on removing the hoses easily? It's a tight fit and I don't want to destroy anything. The car is a 92 model so the rubber hoses etc. don't feel liek the best condition so yeh

[hamgatan]

I'll be trying this on teh 7M in the next few days... sometimes the idle drops veeeery low (<500rpm) to the point it nearly stalls, jab the go pedal and it jumps back up to normal smooth as a babys ass 7M idle (650ish rpm)

hopefully this fixes said problem! shall let the thread know!

Chris

that could also be your shitty stock 7M blow off valve. have you got it vented to the atmo? if so, trust me, plumb it back into the intake before the turbo.. guarantee you itll never do it again.

[4agerolla]

that could also be your shitty stock 7M blow off valve. have you got it vented to the atmo? if so, trust me, plumb it back into the intake before the turbo.. guarantee you itll never do it again.

nah it seems to be plumbed back properly, unless theres a leak somewhere, but i havnt given it a proper check.. cleanong the iscv certainly helped, cant recal the last time the revs dropped off now....

chris.

[RObErT_RaTh]

I know this is kind of an old thread but after many issues lately with my car idling poorly and stalling when cold when clutching in and stopping for traffic etc I decided to clean the ISCV. With the help of this guide and TSRM I solved my issue and car works sweet now! Thankyou! +rep!

[ms53wagon]

my ISCV on 1jz-g does not step out to the open position once car is turned off........is it meant to do this? i think i read that it was a few posts back.
the car will never idle when cold either, pain in the butt...!

[wasfishing]

Dont know if this is whats wrong with my car , but if u have the aircon on wen the cars cold (Idles higher normally to warm up) it will jump between 1500-2000rpm could this be my problem?