Re: 1991 Audi 90 diagnostics

[turbo@steelcity.net]

Mark Zvolanek wrote:
> 
> Phil
> Thanks for extensive description on fault codes.
> 
> You say the prerequisites are:
>   Fuse 24 OK
>   Control unit power OK
>   Engine warning lamp OK
>   Fuel pump relay OK.
> 
> Strangely enough I dont have fuse #24, my fuse box only has 21 fuses. It
> is the one near the engine bay, close to (under) the wind screen on
> drivers side isn't it?
> I dont seem have the engine warning lamp either.
> Few weeks ago I even took out the instrument panel to check it out.
> I only have four lamps on the lower half of the instrument cluster, there
> are holes fore some more lamps, but there is what looks like Audi
> authorized sticky tape covering empty holes.
> Looking into Bentley engine warning light space is taken by "air bag"
> lamp shade, I could tell when I looked at it against ligt. The wires (as
> indicated in Bentley) for the warning light are not even at the connector
> (the pin has no wire) that connects to the back of the instrument
> cluster. None of the unused holes did have engine symbol shade.
> This morning,before I went to work, I started the engine a put a spare
> fuse into the fuel relay, just to see if any of the other lights would
> light up, but nothing lit up.
> Now here comes the strange bit, after I removed the fuse from the relay,
> with the engine still running, the revs suddenly went up from 1000RPM
> (engine still cold) to 1300RPM and there the revs started pulsating
> between 1200 and 1300 RPM, up down up down up down in roughly two second
> intervals. I got spooked.
> Anyway so I drove off and at each give way sight the revs were doing the
> same things up  down etc.
> Untill I went up a hill, where I had to put my foot down and the revs
> stopped pulsating.
> 
> Would you have any ideas what is happenning here?
> And also what about my engine dignostics, what else should I try?
> Are there any other Australians or New Zealanders out there with 1991
> Audi 90 2.3E (NG motor) that were able to read the fault codes.
> 
> Mark Zvolanek
	 YES your engine would rev up after the fuse was removed you entered
the diagnostics mode. Fuse 24 is not in the fuse panel but right next to
it on the front edge of the fuse panel box.Could be what you thought was
a spare I have seen this many times.
turbo