ybturbo

Hi all! Today I installed my new ACT sensor and also cleaned the throttle body, ISCV and checked TPS. The car is well inproved on traveling and on boost (the engine became more "elastic" of boost and it seems that it gained some power on boost and also a slight missfire on 2000rpm with no load it's gone) but the now the idle sometimes is 1200rpm when warm. The base idle is set to 900rpm with ISCV disconnected and engine on normal operating temperature. When I plug the ISCV in the idle doesn't changing but if I give it a blip of throttle then it is idling on 1200 - 1300rpm and doesn't drop unless I give it a big blip of throttle(3000rpm). I don't know about the status of ECT but the TPS seems ok(resistance - resistance while traveling etc...) ,ISCV is cleaned and doesn't stick at all and I guess that CO should be OK since the car passed emissions test 2 months ago and was fine. Any opinions about this? I will check the sensors and wirring tomorrow but what is propably causing that?

ybturbo

Anyone any ideas?

ybturbo

Today I check Co and it's perfect, idle was a little bit lower than 900rpm so I raised up to 900 (measured with the exhaust analyser so it is spot on), ECT is ok, ,ACT is new, TPS is 0,5V on idle and increases as throtlle is increased, MAP is ok, CPS is ok, Phase sensor is ok and by the way all sensors measured from the ECU multiplug so the engine loom is also ok. Why the ISCV is making the car to idle on 1200 - 1500rpm if you give it a little throtlle and is ok if you give it a large blip of throttle? Nobody has experienced this before? By the way I unpluged the ISCV because it was getting on my nerves at every trafic light!

cozmeister

iTrader: (1)

You may have a sticky idle control valve - remove it and clean its dirty innards out with carb cleaner, then refit it..

If you have an L6 ECU with the PF01 TPS, the TPS needs to be aligned correctly as it has a switch inside that tells the ECU that the throttle is closed. If your TPS is not aligned correctly, the ECU will believe the throttle is open slightly, even if the throttle is closed.

I just read your post again - you say the TPS voltage is 0.5v, so I guess you have an L8 and PF09.

ybturbo

Yes L8 ECU with PF09 TPS. The ISCV was cleaned before and yesterday dissassembled, cleaned and reassembled correctly and also the plunger inside is traveling quite easily... Could the ISCV be faulty since I don't have oscilloscope to check the voltage that the ECU is sending to it to judge that it is correct or not.

BigPeBe

Are you sure the throttle is closing properly? Mine does this sometimes even without the idle control valve, but when I open the bonnet and "manually" close the throttle from there it lowers the idle where I adjusted it originally.

Also the blip on the throttle can fix it because the throttle closes in faster speed and causes it to close properly.

ybturbo

Yes the throttle is closing properly... Imagine that I put carb cleaner in with the throtlle body vertical and I blind the idle screw hole with my finger and the throtlle wasn't leaking at all. I opened it slightly and then closed it again and also wasn't leaking after closing...

col93saphcos

iTrader: (2)

hi,possible tps voltage is to high?when i adjusted mine didnt run right till i set it to .28v,maybe worth a try,col93saphcos

JTECH James

iTrader: (13)

check you have no air leaks, ie leaking dv on the vac side, etc etc

ybturbo

Well I have no air leaks the idle rise is just from the ISCV and I know that the ISCV on my car never worked as it it suppossed to do : it wasn't rising the idle with funs on, on first start from cold the idle was just 800-900 rpm and the only think that it was doing is to give the engine some revs for 1-2 sec and then normal idling again but now it idles to high.
The voltage on the TPS is 0,5V and it is as suppossed to be. Can you make it lower by adjusting it and is this right?

col93saphcos

iTrader: (2)

sorry i only mentioned this thinking you had adjusted/moved it,if youve not moved it and was ok before i'd think it would still be ok,col93saphcos

ybturbo

Yes I removed the TPS but I marked the position and placed back in exactly the same place (I 'm sure it is in the same place as before down to the last millimeter) but I also checked it with multimeter for correct positioning and when engine is idling is as per manuals to exactly 0,5V

ybturbo

So nobody knows something? There is first time for everything I suppose...