850 t-5 high and uneven idle issues

[kimon850]

Hello guys,I hope everyone is fine.
for many months now I have a problem as the title says with my 850.the idle most of the times when I first start the car after many hours sitting stays to 1200-1500 rpm.then it may be ok and after some time driving if I stop to a traffic light it may do the same or not.A friend told me that it could be the ECM because everything is checked and double checked,so two days ago I dropped a stock ECM and it was fine for a while,but the next day it did the same.(plus that during the gear shifts the revs would stay up to 3500-4000 without pressing the gas pedal)so I changed again my previous ECM which is tuned iirc with rica's upgrade.for 15g and oranges.and now except the above mentioned symptons it also goes all the time under the usual rpms and over all the time.All the vacuum hoses are changed with silicone hoses checked and double checked.the valve for the idle also replaced with another from a car which is running fine.the only thing that is defective and I know that,is the flexpipe before the catalytic conv. which is before the lamda sensor but I don't know if it affects the idle.

any thoughts or inputs are welcome.
thanks in advance.

[ajc106]

Hi had this fault with mine it was the vac pipe that sits on the end of the inlet manifold by the thermostat its part of the pcv system and runs under the manifold and down to the turbo intake i just got a length of pipe and connected the two together

[kimon850]

thank you for your interest and your help,but the pcv is not working on my car the oil smokes go out.so everything from the OEM system is deleted.Anyway thanks again,you are the only who thought to help.
JUST for OTHER guys info,maybe someone in the future may have a similar problem,the problem was from the wiring harness of the idle valve.and it was affecting MANY things on the car.the car runs better now and stronger,less fuel consumption,and also some other faults that were unsolved are finally ok.THANK YOU ALL!!!

[woz]

Well done Kimon and thanks for the update - it is really helpful like you say, when people post up how they have solved a problem thay have shared with the group.
Cheers - W