B5 S4 No start

[Brett Dikeman]

On Dec 22, 2006, at 9:43 AM, Mark R wrote:

> But when cranking, SHOULD the MAF show airflow?  I suspect that  
> showing zero
> is normal.  I always use my VAG-COM, but I know people pull the MAF  
> wiring
> to force the car into a limp-home map and see if that makes a power
> difference.  Quick and dirty "failed MAF" test.  Any car I see, the  
> MAF is
> weak, and not totally failed.
>
> Knowing that the ECU has some fail-safe mapping, I suspect during  
> starting
> it ignores the MAF input.  But I can't find any definitive  
> literature on
> this in either Bosch or Bentley manuals.

In the 3B, the car will start and drive without the MAF.  Performance  
is atrocious; the car can barely be driven above idle.  I have no  
idea what this means for newer vehicles, if anything.

Back to basics: do you get fuel?  Spark?  At least one of those is  
very easy to check- sniff the tailpipe...

I'd follow the Bentley's no-start troubleshooting tree, since it  
makes few assumptions...and given the car's history, neither should  
you :-)

Brett