E30 325E running rough

[Aviator]

Hey guys. I bought a 84 325E for $400 that shows 74k on the ticker, is in good shape, but runs rough. It's getting tons of fuel somehow. I replaced the fuel pressure regulator, and the cold start valve from a junkyard. Because I noticed fuel was getting through the FPR vaccum line, and fuel was leaking around the outside of the CSV. I checked the plugs and there is good spark. I even replaced the junk autolites for copper NGK's. But this car still runs like ass. Also, the P.O. cut off the cat's, because he thought they might have been clogged. What are some other things that would cause the car to run so rough?

[jmc1590]

Welcome. Congrats on your find. The eta engine in there can be a pain at times, but is usually rock solid.

As far as your concerns go, here are a few items I would check to verify / correct your rough running: Fuel pressure - You replaced the regulator (if I read right, with another one from a yard) but have you tested what the pressure is in the line. A restricted fuel return line can cause your pressure to spike. AFM & O2 sensor - Could be sending faulty data to your ECU, causing a rich condition. I wouldn't worry about the cat, mine runs fine without one. That's just the first things that come to mind...

Get a good reputable manual (read Bentley) and follow the troubleshooting charts.

Good luck!

[Aviator]

Thanks. Where's a good place to get a Bently manual? I really need one.

[jmc1590]

There may be other sources, but Amazon.com has them for $38 including shipping.

[Quadrajet]

On my 84 325e I replaced a bunch of stuff, and it turned out to be my ECU. If it's the one that ends in 021 I would ditch it and get the Green label 027.
It was like night and day.
The ECU lives above your glovebox. I would check to see and avoid some spending.

[Aviator]

That might be it. Because out of the blue it ran really good for a while. This was when I was over looking at the car. Then it went back to running like crap. So he gave up and sold it to me. Where could I buy a new ECU? And how do I check mine to see if it's bad? Thanks.

[Aviator]

OK, just found the ECU, looks like it already has a green label. Does this # look correct?

0 261 200 027

[Quadrajet]

Sorry just got back from having a muffler put on my iS. Yes that's the correct Green label number.
When I had my 021 it would start fine then flood, for no reason what so ever. Or I'd be driving down the road and it would go rich, throwing smoke and bogging like crap.
As far as checking it, I don't know. It could be bad. Also in the '84's there is like an auxilliary temp switch. That should be disconnected as well. Mine kept the same resistance no matter the temp. I'll have to take a pic to show you. It will be a while.
I got a spare 027 off Ebay a while ago. Or wrecking yard, that's how I found the my first 027.

[Quadrajet]

This is the Aux temp sensor

[Quadrajet]

These are the connectors

[Quadrajet]

This is the original sendor at the water neck. With the connector from the harness attached.
Basically disconnect the BLK connector from the sender. Then Disconnect the WHT from the harness connector. Then go direct harness to sender.
From what folks have told me and the info I found in an old TSB this was a "fix" for the 021. And if your car is equipped I'd disconnect it and see what happens.

[Aviator]

I'm kinda confused on what your saying. So, the black wire is just a flaw?

[Quadrajet]

What I was meaning is the items in the photos were a dealer installed fix for the 84e's with the 021 unit. If you had this stuff still hooked up, and running the 027, it would be redundant and more than likely faulty like mine.
So instead of just saying disconnect it, it would be better to have the pics to see what I was talking about. Apparently this "fix" was installed only on the '84's, cuz whenever I mention it to folks who have 85-on cars they don't know what I'm talking about. Matter of fact I looked under the hood of my '85 eta and saw none of this stuff.

[Aviator]

Yeah I noticed a sensor like that on mine, but I'm confused by the 021 fix part, since mine is a 027. I'll try that this weekend.

[Aviator]

So, I disconnect the wire connector at the water neck, and hook it up to the white wire connetor from the harness? Then what? Thanks.