Author Topic: I need help... (Read 2388 times)

kurtf114 · « **on:** September 17, 2008, 02:37:39 PM »

For the longest time my idle has been screwed up on my 318. It all started when my friend was messing with the throttle cable, and ever since it bounces from 500-1500 rpms, randomly. I did the pedal trick, and it said TPS, so I replaced it, it was good for about, 10 minutes. Another thing is when I'm driving down the street and I'll be driving at a steady pace with out moving my foot off the gas, the check engine light will come on, the minute I take my foot off the gas the CEL turns off.

I'm almost starting to think it could be a vacuum hose. Some mornings when I come home from work(I work nights) the car has hesitates below 2500rpm.
Another problem is inspection. I cant pass emissions. I replaced my obviously worn out cat-back, which made it a little better but still no go. I think my cat is shot so I'm gonna try replacing that. Buttttt, the DMV says my Idle is too high (WTF?), it idles around 800rpm, I can't see that as being high.

any help is appricated. I wanna get my car running good and pass inspection so I can throw my springs on

Jimmy Lewis · « **Reply #1 on:** September 17, 2008, 04:03:18 PM »

I would definitely inspect the vacuum hoses. I would also pull the plugs and inspect them, maybe pull coil wires while it is running to make sure you don't have a bad wire. Vacuum leaks are prevalent on these cars, it wouldn't be a bad idea to search for the TB heater delete, and the subsequent replacement of hoses. I would imagine that a bad o2 sensor would throw out a code, so it probably isn't completely bad, but it wouldn't be a bad idea to just replace it, they are wear items afterall. Before you spend a load of cash on replacing the cat, do all of the free or very cheap stuff first. When you know the vacuum system is completely leak free, then move onto the other stuff that could potentially cause an idle problem. I can also promise you that the same issue is causing your idle, sub 2500rpm stumbles, and failed emission. My money is on a large vacuum leak under the upper manifold where like 78 different coolant and vacuum hoses are snaked together. Goodluck.

kurtf114 · « **Reply #2 on:** September 17, 2008, 08:25:40 PM »

thanks for the reply, bimmerforums was no help, so I signed up here. Tommrow I'm gonna pull the intake manifold off and just replace all the hose's. Also, what is the TB heater delete, and what does it do? I'm gonna search that right now.
The deal with my car is... I used to have a 93 318is, but I totaled that. I found a 95 318i with a motor that was no good. So I swapped them and I got the 93 motor in the 95 shell. So I have a whole parts car laying around. The motor out of the 318is only had 50k miles, so the cat out of that is pretty newish. So I'm gonna throw that one on if I have too.

Oh yeah, I have a friend named Jimmy Lewis, so I had to double check to make sure that you weren't him lol

tjts1 · « **Reply #3 on:** September 17, 2008, 10:10:52 PM »

It seems like at least 1 person a day come here with the same symptoms. Heres the fix.
http://www.m42club.com/forums/showthread.php?t=2742
Good luck

AcSchnitzer318is · « **Reply #4 on:** September 17, 2008, 10:36:38 PM »

I wish that was always the solution

Fixes 90% of problems though...