Toyspeed.org.nz Message Board

by **matt dunn** » Wed Jan 06, 2010 11:11 pm

Maybe that problem combined with the brakes problem could be a faulty brake booster?

Try blocking off the vacuum to that?

Checked the obvious like
the throttle cable not holding the throttle open,
idle screw adjustment on the ITB's,
Check the TPS Idle contact is set right?

by **ChaosAD** » Thu Jan 07, 2010 8:22 am

If you have a catch can fitted, make sure the fitting on the top of the inlet manifold is blocked off.

I found with an auto blacktop ecu my 20v would idle cold at 2000rpm and warm 1500rpm but the idle was fine when I swapped in a manual blacktop ecu.

Your car hasnt had a manual conversion has it?

The iscv is a 3 wire pwm valve. The ecu will alternately ground one coil then the other a at a rate of about 250Hz (4ms), it will adjust the duty cycle to alter the amount of air it lets through.
My silvertop idles nicely with a duty cycle of about 40% (or it could be 60%) when warm.

When adjusting idle speed screws etc, dont touch the ones under the trumpets, they are for balancing the itb's.

OMG so shiny! · by **Dell'Orto** » Thu Jan 07, 2010 6:03 pm

Ok fixed brakes - just needed one hell of a bleed with a pressure bleeder, got millions of air out

Cold idle is still high, so will have to have a fiddle with the bits mentioned. No catch can, the car is mechanically stock and is factory manual.

by **whynot** » Thu Jan 07, 2010 6:13 pm

I did my idle valve the same time as yours and it still idled high until I changed the o2 sensor, it made a huge difference but the old one was all carboned up

OMG so shiny! · by **Dell'Orto** » Sat Jan 09, 2010 9:11 pm

Ok, so checked codes before, still nothing - BUT, when I turned it on with diagnostic still bridged, the cold idle was 1200ish rpm, and once warm dropped to 800. Timing was at 8 degrees, so put it to 10. Now the warm idle sits at 1000rpm, though if you drive and come to a stop, it hangs at 1500rpm for a few seconds then drops to 1000.
Any ideas?

by **sergei** » Sat Jan 09, 2010 10:18 pm

What is the temperature like when you drive?
Does it go down?
Have you checked your thermostat?

OMG so shiny! · by **Dell'Orto** » Sat Jan 09, 2010 10:49 pm

Temperature sits at halfway, doesnt move. T/stat was supposedly replaced late last year.

OMG so shiny! · by **Dell'Orto** » Sat Jan 16, 2010 6:18 pm

Found a leak at the inlet manifold gasket, so replaced that....made next to no difference :evil:

Looking around for other leaks, I noticed the little black thing on the firewall (with one hose going to the intake pipe and one going to the vacuum block) was hissing quite noisly, so pulled the plug and the idle instantly dropped.
Question now - what is that thing?

by **Mr Revhead** » Sat Jan 16, 2010 6:26 pm

stick the part number into google

OMG so shiny! · by **Dell'Orto** » Sat Jan 16, 2010 6:45 pm

192000-3042 = A/C idle up solenoid. WTF, dont tell me that thats whats been causing it the whole time :evil:

Website · by **Bling** » Sat Jan 16, 2010 6:59 pm

Will you lol or rip more hair out? :lol:

OMG so shiny! · by **Dell'Orto** » Wed Jan 20, 2010 5:46 pm

Replaced the ECU temp sensor last night, we now have a decent idle

Still takes a while to drop to sub 1000rpm, but at least it now only cold idles at 1400ish rpm

by **Mr Revhead** » Wed Jan 20, 2010 5:48 pm

That'll be one goat please

OMG so shiny! · by **Dell'Orto** » Wed Jan 20, 2010 5:52 pm

Should FAQ this thread, think I covered damn near every possible cause of a high idle :lol:

OMG so shiny! · by **Dell'Orto** » Thu Jan 21, 2010 5:58 pm

No, car decides it still doesnt wanna play ball. On the way home from work this afternoon it started idling at 2k cold again. Unplugging the AC idle up did nothing this time, and once its warm the idle bounces from 1500 to 2100rpm. With the AC idle up plugged in it'll idle at 1500rpm warm.

What the $&#$% else can I do??!?!?!?!?

by **Mr Revhead** » Thu Jan 21, 2010 6:17 pm

Take it to a mechanic

And plug in his scan tool

Website · by **Bling** » Thu Jan 21, 2010 10:21 pm

Slap a carb on it, will make more power that way too I read somewhere :lol:

by **fivebob** » Thu Jan 21, 2010 11:04 pm

Take all sources of air entering the plenum after the throttle body and block them off one at a time. If the idle changes then you have identified the device that is causing the high idle

If your idle does not change after doing to all sources of controlled air that enter the plenum then chances are that have an air leak somewhere.

OMG so shiny! · by **Dell'Orto** » Wed May 19, 2010 6:31 pm

Gah, after months of behaving nicely, its started to play up again. Will idle good when cold, but after ~4 minutes the idle starts bouncing from 1800 to 2500rpm. Can hear the ISCV opening to try and bring the idle down, but doesnt really help. Oddly, turning the car off and on again fixes it for another 4ish minutes.
Is it possible the ECU is causing these faults??

by **sergei** » Wed May 19, 2010 6:36 pm

Dell'Orto wrote:Gah, after months of behaving nicely, its started to play up again. Will idle good when cold, but after ~4 minutes the idle starts bouncing from 1800 to 2500rpm. Can hear the ISCV opening to try and bring the idle down, but doesnt really help. Oddly, turning the car off and on again fixes it for another 4ish minutes.
Is it possible the ECU is causing these faults??

Is the ecu standard? Checked for leaky capacitors?

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