car idling low.......

[mr_240sx]

ok guys tonight was a good productive night for me and my luck with 240's seems to have changed. everything went off without a problem.


ok heres my problem since bings meet.

car is idling ~550-600rpm and will drop down to 400 the odd time and either stals or comes back.

anyways during idling at 550-600 the air fuel is anywhere from 15.5 - 16 and when the rpms drop to 400 the a/f goes to 17-17.5 and often drops off the chart.

just wanted to know what idling a/f should be at while idling. also when driving, what a/f becomes unsafe/dangerous?

also it seems that once i took off the iacv screw and blew compressed air in there the car seems to be steady at 600rpms and 15.5-16 a/f wise. inside the iacv and the screw itself was covered in black dust. would this be causing my problems?


also i havent driven the car yet with the wideband as i just finished everything up and is too late to go test it out. but when i rev it in neutral past 10% throttle, the a/f goes anywhere from 11-14. which leads me to beleive that all i need to do is turn the idle up and it would fix everything? because when i put it around 750 using the pedal, the a/f goes to 15 and seems to be idling much smoother.


anyways anyone know where the idle control screw is?

[cotbu]

Check for vacuum leaks. Then if none are found, set car to timing mode(warm car to operating temp, shut car down then remove TPS, rev to 3grand 3x, check idle, increase idle to suit @ IACV, then rev to 3grand 3x to lock it in, let idle shut down car plug in TPS. Start the car. What's the Idle?

14.7 if you still have a stock 02sensor, ecu controls the idle AFR

[mr_240sx]

well im still running stock o2 sensor to my knowledge. im gonna try that and also check my timing after work today. also

just got back from taking the car for a little ride.... well under acceleration the a/f is anywhere from 11-13 which im pretty sure is fine. anyways its when i left off the gas and the car just coast is when the a/f goes from 16 to right off the map. which when it does that my vaccuum drop to -25 which never used to go past 20 except for when i would try to stop in a hurry and the odd time it would go that low temporarily until i would be stop. anyways when im menouvering in my driveway and rev it, as soon as i let off, i hear a whinning/whistle sound and during htat sound my a/f goes to 16+. from inside the car it sounds liek my bov not sealing properly. but if that were the case would it be running rich instead of lean?

[mr_240sx]

well i drove the car ito town....and the whitleing noise seems to be coming from the bov. its either sticking or staying open but only when the car is idling or coasting. so ill try to tighten the adjustment screw ...and ill go from there.