Car dies at idle , Runs fine at 2k+ , help a noob?

[SSE30]

Hey r3vers , my e30 is having some problems.

Symptoms:

- trouble starting
- cranks over , but idle is spastic
- When driving and shifting it runs fine.
- As soon as I slow down , and revs go under 1200 , car dies

VIDEO OF SYMPTOMS:
http://www.youtube.com/watch?v=ejDiPYrS3jQ
(Notice the car dies after I rev it)

I noticed there was a crack in the intake boot , so I wrapped it with some duct tape , but no luck. I also took out all of the plugs/wires and cleaned them.

Things I think may be wrong:

Fuel filter
02 sensor
ICV

I would appreciate any help , or advice on what you guys think it is.

[Matt-B]

i been running my m50 for 10-15 minutes at a time to bleed steering etc, no o2 plugged it, wont make care idle and not run

ICV, throttle switch, AFM

or that weird noise, big vacuum leak perhaps

[SSE30]

i been running my m50 for 10-15 minutes at a time to bleed steering etc, no o2 plugged it, wont make care idle and not run

ICV, throttle switch, AFM

or that weird noise, big vacuum leak perhaps

I'm going to check the icv for dirt build up. I think it may have gotten dirty when the intake boot was damaged. Thanks for the advice.

[SSE30]

Has anyone else heard of or experienced these problems? I just don't want to throw parts at it blindly. Thanks!

[blalor]

Does it still do that once the engine's warmed up? Mine also seems to exhibit some of the rough idle problem, but it seems to become normal once warmed up.

[SSE30]

Does it still do that once the engine's warmed up? Mine also seems to exhibit some of the rough idle problem, but it seems to become normal once warmed up.

No it is permanently rough at low idle , regardless of it being warm/cold. I think it has to do with fuel delivery.

[mr ilia]

I had similar symptoms with my recently acuired '91 318i. It would take a looong time for engine to fire up, regardless of if its cold or warm, it would not hold the idle idle and bog down/hesitate with gas to the floor and it would misfire if revved past 4500rpm.

As I did not know history of the car, I ordered several key parts from the web, parts that I thought would have some sort of relation to my problem. Once it was all installed, the motor started right up and hodld the idle and drives very well. I'd say it got fixed up 100%.

This is what I did:

-changed to another ICV (used)
-changed AFM (used)
-new drop in K&N air filter
-put new fuel filter (new)
-put new fuel pump (Walbro)
-installed new spark plugs wire set (new to fit 1984 318i)
-new Champion copper spark plugs
-cleaned up all ground connection at the coilpack and the ground junction wiring at the firewall
-did TB heater delete

[davem]

Sounds like it's idle specific... so my guess is vacuum leak, coolant temp sensor, o2 sensor.

[coruja08]

just change your AFM thats it man trust me

[JrCamacho]

my buddies 318is is doing the same, i just replaced all the coolant hoses, thermostat and housing, plastic water pipe, after initial start up it sounds exactly as you proclaimed...

I have yet to replace the AFM as the check engine light throws a 1215 with the stomp test..

i will let you know once i replace the AFM and test.

[Tricky8]

I had the same issue and it ended up being the ICV.

[JoeyBones]

sounds awfully like vacuum leak. Get a piece of flexible tubing to use as a "stethoscope" , one end right by your ear, the other moving along all vacuum lines/hoses... it will really amplify the sound of the air rushing past the end. Works great to diagnose leaks.

[unome]

My engine did something quite similar after a visit to a repair shop. They had switched the connectors for the coolant temp and the oil pressures sensors.

Just a data point...