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Still idling too high

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Old 31-08-2012, 06:16 PM
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BRAMMER
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Default Still idling too high

Right i still have the issue of the car idling high, currently it's at 1400rpm which has dropped slightly since work.

This started when i replaced the TB with a replacement 2wd and changed the throttle bracket to an Airtec item as prior to that it was all idling fine.

I have removed the inlet and fitted new plenum gasket, helicoiled the threads in the plenum so it perfectly tightens up and fitted a new O ring between the throttle body to replace the old cometic item.

The TPS was set at 0.35v at idle before the TB was removed so will still be in the same place now fitted back on..

I have the idle screw pretty much all the way in but i seem to remember that it was half way when fitted to the car once before, so what is causing this?

How to test the ISCV?

Any idea's folks?
Old 31-08-2012, 07:29 PM
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Ridgey
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Best to borrow one (ISCV) and try, i've had to change one once, as the car started idling high.
Don't know how to test them though or if you can?
Old 31-08-2012, 08:13 PM
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botters
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does the idle drop iff you unplug the iscv?
Old 31-08-2012, 09:32 PM
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JOHNDQ
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Are you sure it doesnt have a air leak? might be worth asking a local garage if they have a "smoke probe" to put into the intake system
Old 31-08-2012, 11:14 PM
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Originally Posted by botters
does the idle drop iff you unplug the iscv?
Completely cuts out, still runs the same if the TPS is disconnected

Can anyone comment on the idle screw position, as.I would have thought they would be roughly similar as I said above I could have swarn it was half way in before when the car was setup and running spot on
Old 01-09-2012, 03:09 AM
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Gav Diamond
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Try winding the idle screw out a little at a time bud as the car should idle with the valve unplugged.
Make sure the car is up to temp as will not idle with the valve unplugged when cold
Old 01-09-2012, 08:02 AM
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I've just done that now Gav, plugged the ISCV in and the revs started to climb so quickly disconnected.

So is it looking to be an issue with the iscv?
Old 01-09-2012, 08:58 AM
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Thanasis
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try the TPS at 0.20 - 0.28 and test again,if you have the pf09!!
Old 01-09-2012, 10:38 AM
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Get it warmed up, unplug the ISCV and set the idle to 1000 rpm using the idle screw. The engine should idle fine with the ISCV unplugged. If you can't get it screwed down that low, then there's something wrong. IIRC the TPS will affect the ISCV and therefore the idle speed.
Old 01-09-2012, 10:57 AM
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martysmartie
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Firstly do you have 2WD management, i.e. L1/L6, by your TPS reading I am guessing you don't and therefore have L8?

Get it up to temperature and disconnect the valve, make sure no electrical load is applied and the fans are not running!

Then UNSCREW the idle screw to increase the idle speed (You will need to loosen a locknut first) it's important this is tightened correctly afterwards, else it and the idle screw can fall out!

You want to see around 850 RPM, reconnect the valve, the revs should raise then fall again.

It sounds like at the moment you are using the ISCV to control the idle speed

Martin
Old 01-09-2012, 02:52 PM
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Originally Posted by Thanasis
try the TPS at 0.20 - 0.28 and test again,if you have the pf09!!
I will have to wait to get a reading as i don't have a multimeter here

Originally Posted by martysmartie
by your TPS reading I am guessing you don't and therefore have L8?

You want to see around 850 RPM, reconnect the valve, the revs should raise then fall again.

It sounds like at the moment you are using the ISCV to control the idle speed
Martin it is L8 - i have the idle speed set at temp but when i refit the iscv plug the same applies it revs up to 2000rpm and thats it
Old 01-09-2012, 03:44 PM
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Oh so at least the base idle is set correctly now, I imagine the valve is TPS related, incidentally with L8, unplugging the TPS will not have the same effect as it does on 2WD, actually it will probably make it run worse.

Martin
Old 01-09-2012, 03:49 PM
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Thanasis
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ok Brammer,check the TPS again with multimeter,and check for air leak in your plenum!
Old 01-09-2012, 03:52 PM
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Originally Posted by Thanasis
ok Brammer,check TPS again with multimeter,and check for air leak in your plenum!
The fact it's runs ok without the valve connected shows there not to be an air leak, clearly the ISCV is being told to open.

Martin
Old 01-09-2012, 04:04 PM
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Thanasis
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Originally Posted by martysmartie
The fact it's runs ok without the valve connected shows there not to be an air leak, clearly the ISCV is being told to open.

Martin
i don't have test this case,but before he fit the new plenum the car run perfect..strange! he must check all these

PS,i have the same problem with my hart plenum and i re fitted the original gasket again!

Last edited by Thanasis; 01-09-2012 at 04:07 PM.
Old 01-09-2012, 05:45 PM
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The car ran fine on the plenum originally, but the threads on the Hart are weak and some where stripped so it had to come off to be helicoiled - every hole was done and new gasket and O ring used - i have removed the iscv and stripped it and will soak in petrol for a few hours as it's not 100% bad at all - i do hear you regarding the tps i will check that Monday when i have access to the meter - currently set at 0.35v CT and i beleive i could only get 3.09v WOT due to the Airtec bracket but again that needs to be checked again.

I have set this before at this figure and it ran perfect but their are so many alternative figures out their i think it's trial and error.

One thing the car runs well i just want this sorting

Cheers for the advice lads it's much appreciated
Old 01-09-2012, 05:45 PM
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Originally Posted by Thanasis
try the TPS at 0.20 - 0.28 and test again,if you have the pf09!!
I have had the same problem and indeed this was the solution.! Dont adjust the TPS above 0.3V!
Old 01-09-2012, 06:22 PM
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I'll try it under 0.3v then and see if it makes the difference
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