No Start: Audi 100, 1990, I5 NF engine, non-turbo, non-quattro, CIS-E-111 (California)

[Tony Hoffman]

I think the two wires there are the ones where he says "behind intake
manifold", though that's just my assumption.

I was under the inpression there is only one ECU in the NG/NF cars. I only
recall pulling one when I sold the NG out of the 90, and we pulled the whole
harness with the engine. I ceratinly only saw one in the schematics.
Unfortunately, I don't have them with me, as I'm in Oklahoma right now. When
speaking of the ignition control unit, are you refering to the small module
mounted on a heat sink that has five (I think) wires going to it?

There is no harm in hooking up that ground, and running the car that way
till you can get it repaired properly. Though I still find it hard to
believe the shop repaired it that way. If it had harmed anything else, it
would have been on them to repair.

Send me the part # of your ECU and I'll see if I might have a spare for you
to use for testing/repair.

Tony

On Sun, Aug 28, 2011 at 12:40 PM, Huw Powell <audi at humanspeakers.com> wrote:

> Thanks for putting all the details in one place!
>
> I have two comments.
>
> 1. In your list of ground checks you didn't mention the (2?) wires that are
> grounded to a stud on the intake manifold.
>
> 2. The logic that gets from your symptom and check list to "bad ECU" is
> flawed, I think, since there are two ECUs as you note, one for fuel (which
> also runs all that other junk you list), and one for ignition, which only
> runs, well, the ignition.  Which one is bad?  Both?  Just ignition (no spark
> would shut down the fuel system via the fuel pump relay)?
>
> Hmmm, wait on that, I may be assuming too much across platforms and model
> years.  On my NG-engined 88/89 90Qs there are two physically separate ECUs.
>  Is this not the case with your car?  Did they get around to stuffing them
> into one box?
>
> Anyway, you really should try to borrow another ECU to swap in if you can.
>
> Good luck!