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Discussion Starter #1
Hello,

I have purchased a 1995 318si, and I have 1 problem. When I first got the Bimmer, I started it, and it would idle horrible, and then stall. If I got the RPMs up around 2k it would stay running. I then read the ODBI code using the gas stomp method. Here is the code I received.

1215 Mass Air Flow Sensor Fault

With my new found knowledge I unhooked the MAF, and it idle'd a little better. I took the ICV(Idle Control Valve) and doused it in MAF cleaner, because that is the only cleaner I had on hand. I put everything back together, and now it does not stall, it will bounce from 600~ RPM to 1000 RPM, and idles much better. If I unplug the MAF it stays around 1000 RPM with the occasional slug down to around 800 RPM, but it will IDLE and not stall now.

What are you recommendations, and knowledge of this issue? I've never owned a E36 before, and I'm completely open for tips, knowledge, and all the help and love you will give me!

Thanks!
 

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This is one of the more difficult to diagnose issues just because there are several causes that can give the symptoms you've got and the OBD1 diagnostics aren't much help in sorting it out. Unplugging the MAF puts the engine in open loop operations where it isn't really looking at the MAF and used a pre-programmed mixture for the engine. Did you check the rubber boot between the MAF and the throttle body for any cracks or tears? It's a common fault when the boot gets old and it let's unmetered air into the system. If the boot's good, check the ICV and make certain the control vane moves completely freely and smoothly. If there's any roughness in it then the bearings are likely worn out and a new ICV is in order.
 

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Discussion Starter #3
This is one of the more difficult to diagnose issues just because there are several causes that can give the symptoms you've got and the OBD1 diagnostics aren't much help in sorting it out. Unplugging the MAF puts the engine in open loop operations where it isn't really looking at the MAF and used a pre-programmed mixture for the engine. Did you check the rubber boot between the MAF and the throttle body for any cracks or tears? It's a common fault when the boot gets old and it let's unmetered air into the system. If the boot's good, check the ICV and make certain the control vane moves completely freely and smoothly. If there's any roughness in it then the bearings are likely worn out and a new ICV is in order.

The boot looks immaculate, and I didn't really know to check the ICV for it's "health". How can I check if it needs replaced?
 

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The ICV is just a servo motor with a control vane on the end of the motor shaft. The vane is in the area that you cleaned when you had it out before. To check the ICV pull it out and check to see if the control vane sticks or if you feel any roughness in its movement. If there is then it needs to be replaced. If your MAF cleaner treatment didn't clear all the carbon out of it then you need to get some better cleaner and try to get it cleaned up.
 
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