Very rich/rough idle

[603Racing]

It's that volvo lip and black grill causing the Idle issue.

Maybe I parked to close to your car that's missing a couple cylinders.

[Bullhead]

Maybe I parked to close to your car that's missing a couple cylinders.

[603Racing]

Shooting from the hip today...

Cleaned the CPS, no change, but I did not expect this to change. Cleaned the O2, also no change.

Tested TPS for continuity, worked as designed.

One thing I did that seemed odd... started unplugging things one at at time then plugging them back in while the car was running. TPS, ICV, and O2, none of them really made any difference in idle, very little if any difference. The Temp Sensor made a slightly more noticeable difference, but not much.

I'm at the end of my testing line. I think I may throw a new O2 sensor at it just to see if that helps. It's the only thing that the testing was inconclusive on.

Edit:
What is the voltage/signal to the ICV supposed to do when the TPS comes off idle? I know what the ICV is supposed to do, just don't know what the voltage/signal to it does when the TPS moves. Because on my car there is voltage between all three pins, varying from 3v to 9v depending on which pins I test. This voltage to the ICV never changes when I move the throttle, while the key is on/engine off.

[603Racing]

Update...

Replaced O2, no change.

Next steps I guess, check O2 signal and TPS signal at the ECU. After that I'm completely out of ideas and that shit sucks.

[603Racing]

I have checked O2 and TPS signals at the ECU. Everything is within spec. Replaced the temp sensor, no change in idle. Also replaced cap/rotor as part of general maintenance. This improved cold start a bit, but no overall change in idle.

Something of note: when it is cold and I first start the car and it idles really rough, if I unplug the ICV it has no affect on idle. This may be normal?

[BruceJ]

Couple Ideas....

Have you tried cleaning the ICV and associated piping?

I have a shakey idle (no noticeable change in RPM) while in drive when fully warmed up. Pretty sure this is closed loop and while the ICV may get the correct signal, executing may be a problem.

http://www.r3vlimited.com/board/showthread.php?t=111370

https://www.youtube.com/watch?v=ZbF0V7nlxao

OR.....other posssible issues that Im gonna review as well:

http://www.r3vlimited.com/board/showthread.php?t=250384

post #7 http://www.bimmerforums.com/forum/sh...rew-adjustment
post #16 http://www.bimmerforums.com/forum/sh...AFM-Adjustment

lots of info: http://www.verrill.com/car/idle/e30_idleproblem.shtml
and more: http://www.verrill.com/car/e30_idlefaq.shtml
Good luck

[603Racing]

I have previously swapped the ICV and AFM from another e30 that idles perfect, no change. The only sensor that is not new in the last 3 months is the TPS. I have checked it for continuity at idle, off-idle, and WOT. All of which check out correctly.

Checked out all the links above, some good info, but I've tried most of it or it doesn't apply. My only thought now is going back to the C191 plug which I replaced with a weather pack plug nearly a year ago.

[tim88325is]

Did you end up doing a compression and leak-down test just to make sure? I don't see it much here but more old-timey mechanics will do these tests right away to create a baseline.

What is the history with the rebuilt head, like someone who knows these heads or just a machine shop?

[603Racing]

No recent comp or leak-down, just the smoke test. Now that I have replaced the O2 and temp sensor, I'm going to check the signal at the ECU again to make sure it's within spec.

[e30onBBSs]

I'm not sure if you have seen this, there is some stuff in here that you haven't talked about so it might help! It talks about a switch that controls the ICV so if your switch is broken it might be the reason the good ICV didn't work.
http://www.pelicanparts.com/BMW/tech...leshooting.htm

[603Racing]

Most of the vacuum lines were replaced in the last 3 years. I did do a smoke test, as mentioned, with no leaks.

I gave up... taking the car to a local BMW specialty shop. I will be working in close contact with them to troubleshoot. May also throw another set of injectors at it just to see. I have a set I'm going to rebuild and test.

[TRIZZY]

Damn I just read the whole thread, now I'm really curious to find out what the problem is cuz i have idling problems as well.. keep us posted!

[603Racing]

I'm going to come back to the mods I have. Does anyone with similar mods (list below) have this problem? The current thought process is that it might be tune related. Swapped ECU's to one without a chip, it comes off idle with throttle input somewhat better but does not fix the issue.

Schrick 272 cam
Mark D 93 octane 17#/19# chip (currently running 17# injectors)
headers
cat delete

[E30-325iS]

Check that you are getting a varying resistance between pins 7 and 12 at the Ecu connector when you move the flap on the AFM.
I think the Ecu wil go into some sort of default mode if it does not detect the AFM.

[603Racing]

Check that you are getting a varying resistance between pins 7 and 12 at the Ecu connector when you move the flap on the AFM.
I think the Ecu wil go into some sort of default mode if it does not detect the AFM.

I have not tested that or even thought about that. Good idea, thanks.

I'm also working with SSSquid to get a custom chip for my exact setup. I love my Mark D chip, but not sure it's optimal with my exhaust/cam setup.