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Trouble getting dagnostic codes from an E30

Discussion in 'E30 (1984-1993)' started by Arash2002tii, Feb 6, 2010.

    Arash2002tii guest

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    The car is a '88 325is, I use the exact method specified for pulling codes on http://www.verrill.com/car/e30_faultcodes.shtml and nothing happens. It does not even flash the code to show that there is no problem with the car. The problem that the car has is that it will sometimes start to die and then come back to life (happens when car comes to idle after being driven), then it starts to hesitate and stutter when driving as if there is a fuel pump or afm problem. Any help is appreciated.
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    az3579

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    What I don't understand is how could codes be flashed via a check engine light if an E30 doesn't have one?

    Arash2002tii guest

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    That's what I thought too at first but there is definitely a light there and it definitely does say "check engine". Maybe I'll take a picture of it next time my buddy comes around.
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    granthr

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    My 1991 325ix has a check engine light. It has only ever came on once, it was at 12,000+ feet in Colorado. It went off once I got back to sane altitudes! :)
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    MGarrison

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    You may have motronic 1.1 and not 1.3 - Bentley manual mentions the 1.1 diagnostics but not 1.3; For 1.1 the codes flash automatically, if they've been triggered, with the key in the 'on' position (turn the key fully but not to start).

    Indicates air flow sensor malfunction, O2 sensor malfunction or parameters exceeded, coolant temp. sensor, or throttle switch malfunction.

    Arash, you might want to check your idle control valve. Bentley manual chapter 6, section 5.3, p. 26.

    Arash2002tii guest

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    I tried it for both ways with no result. I was thinking the idle air control at first but I don't see how that would cause drivability problems. Are there any pins you can ground on the diagnostic port in the engine bay? Or a special reader to get the codes? Thanks for your guys' help
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    MGarrison

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    I also meant to mention - I think it's relatively typical for the si panel to suffer solder breaks - it's possible the system is trying to throw codes, but the display is out either due to a burned-out bulb or bad connection on the board. You could try a Peake Research tool to check whatever else is available, or you have to find someone with the full scale diagnostics, which either a dealer or indy shop would have, unless someone decided to spend a big chunk of change.

    ICV is one of the numerous things related to driveability - read section 3 of the Bentley manual, and what I mentioned already.

    Arash2002tii guest

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    Thanks, I didn't know about the solder breaks. I'll check into that. I'll also look into those Peake tools. And I would read section 3 if I had a Bentley to read out of :(
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    MGarrison

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    Ah- get one, invaluable for tackling your E30. Sorry not to elaborate more, but the manual specifies so many different things to check and how to check them for driveability and idle, it would take 1½ hours to summarize it all into some ridiculously lengthy post.

    A quick start to check the icv - unplug it when the car is running, Bentley says idle should go to approx 2000 rpm. Then, with car off, resistance between the valves terminals should be 9-10 ohms at 73°F; Also says to remove air hoses and connector, and jumper the terminals (wire hooked to battery pos. should be fused) with battery voltage. Valve should close tightly when voltage is applied, open when not - after that there's about two more pages covering tests and expected results.

    Arash2002tii guest

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    I definitely would pick one up but this is for a friends E30, maybe I'll force him into buying one. I'll try those tests tomorrow. Thanks again
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    az3579

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    I just found out over the weekend that I guess the later E30's had a check engine light. I saw the place for it when I pulled my instrument cluster a few nights ago, and since I replaced my cluster with a later one at one point, I now have a bulb in there with the two wires cut for it, so I've no idea where those are supposed to connect so I could check for codes with the new engine. Oh well.

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