[V8] Testing Fuel Injectors, stumble, miss

[dsaad at icehouse.net]

One trick I have used is to unplug the O2 sensor. This should force the ECU 
into a failsafe openloop mode. If your surge goes away, you can assume you have 
some sort of mixture problem. If it does not, maybe ignition problem or erratic 
fuel pressure or ???

Mine seems to run pretty good with the O2 sensor unplugged. Mileage and power 
are probably reduced but it runs smooth.
Do you have access to something like VAG-COM? That may give you some clues too.


Dave


Quoting "Korn, Bob" <Bob.Korn at Fike.com>:

> Anyone know an easy way to test fuel injectors or is this a job for
> someone
> who has the proper test equipment?
> 
> I've done the test using the ECU and they all buzz or click accordingly.
> Pulled them all and replaced the seals and caps, used the NAPA kit that
> crosses to a ford previously mentioned on the list. The caps are
> slightly
> different, had to modify slightly before installation. 
> 
> Still have a miss or stumble under steady acceleration.  Could a bad
> fuel
> pressure regulator cause this?  I do not have a pressure gauge
> set......yet.
> May have to bite the bullet and go buy.   Getting frustrated, been
> chasing
> this one for awhile.
> 
> New plugs, caps, wires, rotors, and Fuel pressure reg 25K ago.
> Since miss started:
> Techron through two tanks fuel, always AMOCO Premium.
> New O2 sensor
> New fuel filter
> New breather hoses
> New seals on injectors
> 
> Any ideas???
> 
> I keep thinking fuel with all the new ignition components. Guess you
> never
> know, better go back and check spark in all the holes.
> 
> 
> Thanks,
> 
> 
> Bob
> 90 V8Q 135K Pearl  
> 
> 
> 
> 
> _______________________________________________
> Audifans V8 mailing list
> Send posts to: mailto:V8 at audifans.com
> Manage your list connection: http://www.audifans.com/mailman/listinfo/v8
> Have an Audi V8 question?  Check the Audifans Knowledgebase!
> http://www.audi-quattro.org/cgi-bin/twiki/view/Audi/V8
> Have a V8 answer? ... Please help others by adding to the KB ... all
> contributions welcome!
>