[s-cars] Fuel Injector Problems

[Mark Strangways]

See if you can check the pressure at various manifold pressures.
Remove the vac line to the top and fashion a device to apply measured 
pressure to it.

As the pressure to it raises, so should the fuel pressure. I am just not 
sure of the ratio.
I sure someone on the list knows.
I had a FPR go wacky, and run ok at idle but not at wot. If went very high, 
and almost ran like a diesel it was so rich.

Mark
----- Original Message ----- 
From: <calvinlc at earthlink.net>
To: "Mark Strangways" <Strangconst at rogers.com>; <s-car-list at audifans.com>
Sent: Wednesday, October 19, 2005 12:38 AM
Subject: Re: [s-cars] Fuel Injector Problems


> It holds steady at idle around 40 psi.  When I give it just a little gas 
> and
> hold it at like 2000 rpm in neutral it fluctuates rapidly between 30 and 
> 40
> psi...I am not sure if this is normal or not.  I was going to try this 
> test
> on the S4 and see if it has the same behavior.  It certainly doesn't 
> appear
> to be running high on pressure which would cause the rich condition.
> --Calvin
>
>
> -----Original Message-----
> From: Mark Strangways [mailto:Strangconst at rogers.com]
> Sent: Tuesday, October 18, 2005 9:47 PM
> To: calvinlc at earthlink.net; s-car-list at audifans.com
> Subject: Re: [s-cars] Fuel Injector Problems
>
>
> How's your FPR ?
>
> Mark
> ----- Original Message -----
> From: <calvinlc at earthlink.net>
> To: "Mark Strangways" <Strangconst at rogers.com>; <s-car-list at audifans.com>
> Sent: Tuesday, October 18, 2005 11:39 PM
> Subject: Re: [s-cars] Fuel Injector Problems
>
>
>>A quick update.  I took out the new injector and sprayed it with Gumout.
>> After placing it back into the fuel rail this immediately caused the car
>> to
>> run worlds better as well as maintaining the fuel pressure in the rail 
>> for
>> a
>> longer period of time...many minutes above 20 psi vs. a few seconds. 
>> This
>> leads me to believe that the rich running condition is fouling the
>> injectors.  It is also doing so in very short order because after letting
>> it
>> idle for maybe a total of 40 minutes the fuel pressure bleeds off
>> noticeably
>> quicker...not the rate it was doing before the gumout treatment but it is
>> definitely quicker.
>>
>> What in the heck could be causing such a rich condition?  I put the O2
>> sensor on the oscilliscope and it is only changing from rich to lean 
>> about
>> once every 4-5 seconds at idle.  The car also tries to initially bog when
>> I
>> give it gas in neutral.  Does this sound like a possible O2 sensor issue?
>> I
>> mean it must be REALLY rich to be doing this.
>>
>> Should I just replace the O2 sensor and find out?  Do you guys recommend
>> the
>> universal splice in type or the harnessed up type that is like twice as
>> much?
>>
>> Thanks!
>>
>> --Calvin
>>
>>
>> -----Original Message-----
>> From: Mark Strangways [mailto:Strangconst at rogers.com]
>> Sent: Tuesday, October 18, 2005 6:39 PM
>> To: calvinlc at earthlink.net; s-car-list at audifans.com
>> Subject: Re: [s-cars] Fuel Injector Problems
>>
>>
>> Can U find a spare ecu for that model ?
>> Maybe the ECU is locking up with impedance problems?
>>
>> Do they hold pressure ok disconnected electrically ?
>> Maybe it's all just coincidental ?
>>
>> Mark
>> ----- Original Message -----
>> From: <calvinlc at earthlink.net>
>> To: <s-car-list at audifans.com>
>> Sent: Tuesday, October 18, 2005 8:28 PM
>> Subject: [s-cars] Fuel Injector Problems
>>
>>
>>> OK guys.  This one has got me totally puzzled.  This is on a '91 200 20
>>> valve but all experience here is applicable.  I have a problem earlier
>>> this
>>> summer where an injector was "hung open."  i.e. it was allowing fuel to
>>> seep
>>> through even after the ignition had been shut off.  I replaced the
>>> injector
>>> with a new one.  Now the new one is having the same problem not more 
>>> than
>>> 40
>>> miles later.  All the cylinders are showing signs of running rich.  Is 
>>> it
>>> possible that they are running so rich that the fuel injectors are
>>> getting
>>> clogged so badly that they are "hanging open"???  Has anybody got any
>>> ideas.
>>> BTW, through some wierd coincidences the injectors, the old bad one and
>>> the
>>> "new" bad one were in two different cylinders, 4 & 5.  I am at my wits
>>> end
>>> and getting tired of working on this thing.  It has been down for almost
>>> two
>>> months due to this problem!  Thanks for any help!
>>> --Calvin
>>>
>>>
>>> _______________________________________________
>>> S-CAR-List mailing list
>>> S-CAR-List at audifans.com
>>> http://www.audifans.com/mailman/listinfo/s-car-list
>>>
>>
>>
>>
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>
>
>
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