Erratic/High Idle, Low Power, Intermittent Stalling
Hi all, first time poster here.
Subject pretty much says it all. I own a 2002 (09/01) BMW 330i Sedan w/ Sport Pkg, stock, which of late is having some problems.
When "behaving", idle hovers between 500-520rpm, which seems and feels a bit low (kinda rough). When acting up, idle fluctuates between 500-750rpm. When being a pain in the ass, idle remains high at 750-770rpm. At high idle, the car stalls/wants to stall under acceleration from stop, doesn't matter if its low/moderate/hard acceleration, though moderate acceleration will keep the engine from dying altogether. Power is low throughout the entire rpm range, though I'm reluctant to take it past 3500k.
So, I'm trying to fix the problem, here's the possible causes I've gathered so far:
1) Bad/Dirty MAF
2) Exh O2 Sensors bad?
3) ICV/IAC (I assume these are the same thing) Bad/Stuck
4) Vacuum Leak
I'm trying to fix the problem in the order of cheapest to most expensive. So I started with cleaning the MAF. No joy. Next, I want to start replacing vacuum hoses as I'm sure at least one is cracked, but have been unable to find a complete vacuum diagram. Does somebody have one? Couple hours of Googling yielded partial diagrams.
Also, gear shifts are clonky, though I think this is an unrelated problem -- I suppose you could technically use vacuum to do some sort of matching -- but I doubt that's how ZF does it.
Any other/obvious causes I might have overlooked? I'm not much of a car guy.
Last edited by BombCenter; 01-28-2013 at 02:58 AM.