e30 newb! need help with idling issue

braden · 08-07-2013, 10:40 PM

Hey guys a picked up a cheap e30 the other week, I'm having some issues I would like a second opinion on. I purchased the car cheap, its going to be my winter beater/ fun car.

A little about the car
1989 bmw 325i coupe, 5 speed manual
Recent timing belt, water pump, all new vaccum lines etc mechanically well maintained.

The issue I'm having with it is at idle the car is shaking and running like absolute junk! Sounds like it has cams, I have been getting a check engine light after about 5 minutes of the car running like a bag. The CEL light comes up on my peak reader as "OA" witch is an emissions control code, more or less oxygen sensor code correct? I'm not sure if a faulty oxygen sensor would be the cause of my idle issues though. The car is running rich but rich enough to choke it out on fuel seems a little extreme, I have purchased a new 02 and will be installing it whenver I get a free second. Just wondering if anyone here has had an issue like this before?

I attached a video
http://m.youtube.com/watch?v=ReXu-yWwACQ

Any e30 nuts that have seen something like this , and know what's causing my issue please! Save me the time troubleshooting :p

Ceeker · 08-08-2013, 10:23 AM

start by buying a service manual for it. ;-)

did you disconnect the dme at any point? if so the car will need to run and be driven for some time to reset and adjust.
Clean your ICV -idle control valve.

have you changed your air filter and plugs?

this is stuff you should do to eliminate possible problems.

are you absolutely SURE you have NO vacuum leaks?? check the PCV hose to make sure it's not cracked especially where it mounts to the valve cover.

also may want to try changing your DME. a bad dme will make the car run crappy. make sure you swap the 173 in as this is the dme which allows to read fault codes from your dash.

karmatose · 08-08-2013, 10:28 AM

Plugs, plug wires. rotor. cap. Inspect all of these.

... and as Ceeker mentioned, get a Bentley.

braden · 08-08-2013, 10:26 PM

I have the bentley book, I have inspected plugs, wires and pulled the cap to check. I will be doing them but there is no signs of excessive wear in the cap and spark plugs look to have been done not to long ago. I have checked all vacum lines for leaks using carb cleaner and haven't found any leaks. I unplugged my ICV today with the car running, the revs went down about 100rpm but the car stayed running the same ( I don't believe that's the way its supposed to be ?) I more put this out there to see if someone has experienced these issues so I can try what they have done to fix this issue before I dive in any farther

e30tOny · 08-08-2013, 11:12 PM

Ceekers advice is very good!

Coolant temp sensor can also be part of the solution.
Some injector cleaner and Shell (has no ethanol additive!!)!high octane gas can work wonders sometimes.

Ceeker · 08-09-2013, 08:31 AM

Quote:

Originally Posted by e30tOny

Ceekers advice is very good!

Coolant temp sensor can also be part of the solution.
Some injector cleaner and Shell (has no ethanol additive!!)!high octane gas can work wonders sometimes.

REALLY? I didn't know Shell gas has no ethanol...maybe I should switch... thanks for the tip. :-)

you still out west?

Bullet Ride · 08-09-2013, 09:44 AM

You can try disconnecting the O2 sensor as well. The car will run in open loop without it.
You should also test the throttle position switch to make sure it's functioning.

e30tOny · 08-09-2013, 12:51 PM

Quote:

Originally Posted by Ceeker

REALLY? I didn't know Shell gas has no ethanol...maybe I should switch... thanks for the tip. :-)

you still out west?

YUPP!...still out west
................just the 91 octane has NO Ethanol!!!