E30 325E running rough

[Quadrajet]

That's it. I actually took the time when I was troubleshooting my problems a few years ago and found the harness kinda does a daisy chain, it's a loop with the three connectors.
My thought is that your car, like mine, had the 021 in it at one time. Hence the "fix".
Bear in mind this happened when I was over at the "tech". I found that temp senser in the pic was bad, it indicated the same resistance no matter the engine temp. So I disconnected it. And my problem persisted. I was chatting with one of the more technically savvy guys there and he asked which ECU I had. Then he suggested the 027. I just happened to find one at my local yard, then threw it in. And the rest is history.
But before all that I had replaced my: O2, FPR,Temp switch,Cold start switch,Plugs,Cap,Rotor. Made sure my cold start injector was working correctly. I spent a bunch of time and money that, had I known, could have been spent elsewhere.
I would disconnect that sensor's connectors and go straight from the harness to the temp switch at the base of the waterneck and see what happens.

[Aviator]

After dinking around with the car I got it running well. But it only runs when a hose is left out from the make-shift intake. This hose goes into the cold start valve area, and is labeled VDO. What is VDO? Tons of air is going through this hose, and when I plug it back into the intake, the car wants to die. As well as when I put a thumb over it.

[jmc1590]

If I understand correctly, you have a hose (which I will guess is about 1" in diameter) that connects to the intake boot and snakes around towards the cold start area of the intake. That would be the Idle Control Valve and it's associated plumbing.

Blocking the ICV should kill the engine (thumb), as it no longer has a source of idle air. Plugging it back into the boot should clean up the idle, allowing the AFM to take back over. Sounds like you might have an obstruction in the air way. (BMW CPR, quick!) Just on a whim, pull your air filter and leave the box open and try to start it again. Also, ensure the AFM connector hasn't been overlooked, and possibly left unplugged.

With the ICV hose disconnected, you are allowing un-metered air through to the engine. If everything was operating normally, this would lean out the engine and cause an idle idle issue. (Can you say vacuum leak?) As the initial post was a concern over what appeared to be a rich condition, I tend to lean towards a faulty (or mal-adjusted) AFM or the cold start injector. Info on the AFM can be found here: http://e28-535i.com/technical/AFM%20Repair.pdf. The cold start injector should only operate when the engine is cranking. (Per the ETM) It's possible that it's dirty or obstructed and leaking. Carefully remove the fuel line from the injector (without breaking off the plastic nipple) and cap off the line. That should "disable" the injector for testing.

See if either of those help.

[Quadrajet]

If you post a pic of the engine compartment and we may a able to see where stuff is routed and help from there as well. When you say "makeshift" it brings all sorts of pictures to mind.
Have you gotten a Bentley's yet? There are some good illustrations in there.

[Aviator]

I need to get a factory 325e intake back on this car. It has a Ford intake rubber piece going from the manifold to the maf or afm. Yes, I said Ford. I'll try and get pictures soon.

[Quadrajet]

OMG! Sorry Bud.

[Aviator]

Here's a quick internet edit pic from qoogle I made. This isn't my car, but this hose looks to be exact. And even though the intake on mine isn't oem, the hose is going into the same place. Why is it wanting to die when the 1" idle control hose is placed in the intake boot?

[Quadrajet]

Well the ICV is supposed to fail in the open position, as in no power=full open. So the only thing I can think of off the top of my head is the hose is blocked for whatever reason.
Because if there in no power to the ICV the ECU will cut the injectors and the result is a fluctuating idle, when my ICV system was dead it would go up to like 2k rpm then dive back down, then back up.
I'll check back in tomorrow. Probably not till around 7 or 8 PT. I'll bring my Bentley's and all my notes from the shop to refresh my memory.

[jmc1590]

Yes, the ICV should fail wide open when power is removed (disconnect the connector from the back to verify), but it seems that the OP's problem isn't related to the ICV. When he re-connects it to the plenum boot, he says it dies. When disconnected from the boot (open to atmosphere) it runs. That tells me that the blockage is not in the ICV hose or the valve assembly.

With the information the it is not a BMW boot, I would start there. It's possible that the "other" boot has some form of breather valve located inside that is preventing or limiting the flow of air to the ICV. Disconnect it and take a look inside. And replace it with the proper one as soon as possible. (A trip to your local salvage yard should provide the needed parts. It seems the only BMWs I can find around here are all 325 etas!)

[Aviator]

Yeah that's it, it dies when I reconnect it into the boot. I need an original intake first of all. Where's a good place to buy one?

[Quadrajet]

Bavarian Autosport is where I've been getting mine.