idle issues on turbo B series.

turbodailydan · Post by **turbodailydan** » Wed Feb 24, 2010 2:04 pm

hey guys right ive had this problem with my Idle control valve since i built the turbo B in my dc2 ITR. basicly what happens is the idle control valve appears to work fine for a while and then it starts to play up.. sometimes the idle sticks quite high at around 1500-2000rpm sometimes higher, sometimes doesnt work at all (more often than not it stops working completly) anyways we checked everything we could think of even changing the idle control valve 4 times with ones known to be working properly. the car is running on ectune, and when the idle control valve starts to play up, it is un responsive to adjustment on the laptop (when its working correctly you adjust the idle up or down on the laptop and the rpm will obviously respond to the adjustment, however when trying to adjust the idle through ectune once the idle control valve starts to play up, it does not respond at all..) however if you replace the idle control valve with another it starts to respond again, but it doesnt last and ends up like before. idle control valve checked voltage and wiring to idle control valve from ecu changed ecu have reached a dead end as to what to check next so we ended up disconnecting the idle control valve and setting the idle by the TB but its not the best way to do it on a daily driver as it will only idle once fully warmed so cold starts every morning are a real pain.. just wondering if anyone has had this problem before..? thanks alot

pacman · Post by **pacman** » Thu Feb 25, 2010 7:20 am

Are you using a obd conversion harness? Try scoping the output at the ecu and the input to the IACV, when engine/car is cold (possibly temp related!?). If you have substituted both the ecu and IACV with known good units then the circuit would be the next suspect to scrutinise. This may have to be done at seperate times unless you have a multi-channel scope to hand. Have you confirmed ground integrity vs temp on the IACV circuit?

kBS · Post by **kBS** » Thu Feb 25, 2010 10:11 am

does it have fitv?

Post by **Gaskleppie** » Thu Feb 25, 2010 1:05 pm

Sounds like a broken fitv or a vacuum leak.

turbodailydan · Post by **turbodailydan** » Thu Feb 25, 2010 5:32 pm

hey yep running an obd conversion harness. i just checked the 2 wires from ecu plug to iacv plug with the multimeter and the wires are good.

is there anything else the iacv relys on to operate properly? does it work from information from another sensor/s??

pacman wrote:Are you using a ob d conversion harness? Try scoping the output at the ecu and the input to the IACV, when engine/car is cold (possibly temp related!?). If you have substituted both the ecu and IACV with known good units then the circuit would be the next suspect to scrutinise. This may have to be done at seperate times unless you have a multi-channel scope to hand. Have you confirmed ground integrity vs temp on the IACV circuit?

jpjackson · Post by **jpjackson** » Fri Feb 26, 2010 9:00 am

this fitv valve they are talking about is what you need to check, i have run into this before. if you remove the 2 Philips head screws and remove the cover the is a plastic valve inside and more than likely it has vibrated loose. remove that valve and put some lock-tight on it and reinstall and see if that takes care of the problem, i have done this before and that should fix it if that plastic piece is loose.

jacer63 · Post by **jacer63** » Sun Feb 28, 2010 3:49 pm

i just removed my iacv and plugged the 2 holes with plugs and reinstalled the iacv.. no more issues

jacer63 · Post by **jacer63** » Sun Feb 28, 2010 3:50 pm

i just removed my iacv and plugged the 2 holes with plugs and reinstalled the iacv.. no more issues

pacman · Post by **pacman** » Tue Mar 02, 2010 5:37 am

Are you using a obd2 iacv (3 wire)? Do you have the original itr inlet manifold fitted? Could be fitv if you are using obd1 throttle body, obd2 do not have them. The iacv should control rpm vs engine temp.