weird accel. problem
 

Ok, this problem has been weirding me out for a while now. When I bought my car in December, the air mass sensor was shot, so idling was erratic, and the vehicle usually stalled. Now, when the car is still cold (Needle in the blue, torward the warmer end), I get a super clean burn with no hesitation whatsoever. But, when the vehicle warms up, there is pretty severe hesitation until I climb up to about 3k RPM's. I thought at first oxygen sensor, but the guy claimed it was recently changed (he also had the papers to prove it). I'm in the process of changing my fuel filter as well, but has anyone looked where that thing's at? Holy crap! Not a 10 minute job! Any thoughts are appreciated!
P.S.-If you've got a tip on the fuel filter, I'm listening!
BMR BOY
'93 325i Sport package - 5-speed; 4-door--Laguna Green Metallic
18" Falken Koblenz: 5-spoke, 3-piece rims w/Falken HK-451
Dinan Chip and full exaust
Cold Air Intake Kit
50% reduced throw short shift
Cross-drilled rotors w/M-Power brakes
Eibach Anti-sway front & rear
HID headlight upgrade w/driving lights
OEM clear taillights, clear markers w/PIAA Plasmas
22% Carbon tinting on all windows
ICE: Alpine head unit, soon to be replaced by Pioneer
mobile theatre, w/DVD. Phoenix Gold subs; MTX Amp.

Just an idea but, check your vacume hoses for cracks / splits.
I had a split at one end once and that made my idle very eratic when the car warmed up.

Good luck. :D

Ian
'97 Ti Sport
DASC, H&R coilovers

did you have your ignition system checked?

Sounds like your DME & coils are going bad >>need to do a smooth running test on it>>It will show which coil is the worst But all 6 have to be changed along with the DME>>or the old DME will continue burning ur new coils>>>and the easiest way to change that filter is to take off the hose from the fuel line first then loosen the clamp around it and push it out the bottom :(

Thanks for all the input guys, but I have a few more questions: First, I should mention that I had replaced the air mass sensor first a while back, which solved the erratic idling. It also caused the check engine light to go out (thanks to Jered and his magical codes). So the car IDLES 100% normal (about 650 rpms). The problem is just the warm temperature acceleration. Is there a way that I could do any of these tests at home? And what is the DME exactly? All your help is appreciated! Oh, and the fuel filter change will be attempted tomorrow probably. Still doesn't look easy!
BMR BOY
'93 325i Sport package - 5-speed; 4-door--Laguna Green Metallic
18" Falken Koblenz: 5-spoke, 3-piece rims w/Falken HK-451
Dinan Chip and full exaust
Cold Air Intake Kit
50% reduced throw short shift
Cross-drilled rotors w/M-Power brakes
Eibach Anti-sway front & rear
HID headlight upgrade w/driving lights
OEM clear taillights, clear markers w/PIAA Plasmas
22% Carbon tinting on all windows
ICE: Alpine head unit, soon to be replaced by Pioneer
mobile theatre, w/DVD. Phoenix Gold subs; MTX Amp.

The DME is the computer(brain)of ur car>>the only way I can think of to check at home if its your coils going ~bad would be to duplicate the miss>>then disconnect the coils one by one.....if it runs alot worse then its prolly NOT that coil....find the one that doesnt effect the idle and thats the bad one>>but the correct fix(if thats the problem)is to replace the DME and all the coils>>plugs to while ur there. And better find something to punch while your replacing that fuel filter>>cuz ur gonna get plenty pissed off at the German A<-hole that designed that location.
Also if you havnt removed the DME drain tube out from the firewall>>black rubber drain right behind the valve cover>>coming from the firewall..better do that to..so it will drain better ~:)