View Full Version : need insight on idle issue

06-12-2007, 11:04 AM
my friend bought a 1990 325i 4 door.
was running kinda ruff so i told him to clean out the TB and ICV and he got a good TPS from a friend.It was runing smooth and powerful for 2 weeks. But this morning on the way to work the car was jumping around alot with the idles and being all random (he might have heard back fire also he said) just barely got it back home.
when i did see the car the first time i noticed most of the air piping had small crackes in it (maybe its leting in outside air)

i know this is probly not enough info but any ideas would be helpful.
like things to inspect or look for
something for him to do hehe

thanks guys

06-12-2007, 02:07 PM
(providing it's an airleak problem)

1. go to dollar store buy a spray bottle if you don't have one already
2. fill with water
3. spray various intake components (including booster and FPR hoses) with water from different sides while idling and listen for an improvement in idle
4. once you hear difference (improvement) in idle, you got the spot where the air leak is

good luck

06-13-2007, 01:45 AM
You already found the problem, now just replace all rubber parts that are cracked enaugh. Its a common E30 problem, they crack and let air in, making it idle bad, and hesitate under acceleration....