[s-cars] 92 (early) S4 no start (now not "kinda")

[Tom Green]

Wylie,

Sometimes the absence of codes tells you as much as the presence of  
some codes, and if you clear them after reading them you will know if  
the failure still
exists.  Low fuel pressure does not cause a direct code, but can  
trigger many more codes when improper mixture is sensed at the O2  
sensor.  Ignition failure
can do the same, but maybe too rich.  The basic troubleshooting Steve  
suggests can be a much better way to start than the guessing game of  
looking for the
common failures.  The lack of other codes does suggest sudden failure  
of a critical component rather than a gradual failure with  
performance slowly degrading
or affecting only certain cylinders, so fuel system failure is a good  
guess, but only a guess at this point.  You can also pull the clip  
and ease the fuel pressure
regulator up slightly to check for pressure in the rail, but that  
won't tell you how much and you risk damaging the o-ring seals.  They  
are available to replace
separate from the FPR, but that would be small consolation if the  
fuel is spraying out and none are on hand.  :-)

I doubt the cam position sensor is the problem.  You are probably  
predisposed to suspect it because of the history of intermittent no  
start problems, but surely
a fault code would have been stored on at least one of those events.   
Hopefully there is a quick resolution to the problem, but don't  
forget to revisit the initial
assumptions if solving the issue becomes difficult.  If the speed  
sensor or connection is bad, it can cause a no start condition, and  
the fault code ignored.

I thought at first that Steve said "spray some ether into the intake,  
and run" - all good solid advice.  :-)  (With apologies for  
misreading and then misquoting
the author.)

Tom

> Date: Wed, 12 Dec 2007 17:17:01 -0800
> From: "Steve Powers" <sbpowers at gmail.com>
> Subject: Re: [s-cars] 92 (early) S4 no start (now not "kinda")
> To: theringmeister at triad.rr.com
> Cc: s-car-list at audifans.com
> Message-ID:
> 	<f55c9cce0712121717x413e31d4n193d114c3eeefb88 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> spray some ether into the intake. does it start (and run) then?
>
> that can rule out MANY things...
>
> BTDT, replaced the fuel pump (when it wasn't needed)
>
> Steve Powers
>
> On Dec 12, 2007 1:48 PM,  <theringmeister at triad.rr.com> wrote:
>> i kinda did dave's test. I didn't pull the line, but upon  
>> connecting the wire(s) from the + post to the rear terminal at  
>> fuse #17 i could hear what sounded like fuel being pumped through  
>> the lines right at the entry to the rail, so I pulled the known- 
>> good FP relay from my 90, which aside from the extra posts for the  
>> fuse on top, is essentially the same terminal-wise, and put it in  
>> place of the one in the S4 (on my early 92 it's labeled 87F).  
>> Still won't start, and no codes to suggest anything else.
>>
>> --
>> Wylie Bean
>> TheRingmeister at triad.rr.com
>> 90 cq
>> 91 90q20v sport
>> 92 UrS4
>> 01 allroad