Troubleshooting

[Ben Swann]

Vincent,

You might want to recap what you have done and what overall symptoms you are having.  

Some things to try/confirm..sometimes a little starting fluid directed into the intake
manifold can reveal if there is or not spark.  You might need to remove a vaccume cap to
spray in there, and I think there is a vaccuum port on the side of the throttle body -
use the one inside the throttle - closer to the cylinders.

Remember the fuel pump is ignition primary triggered.  You can try to jumper fuel pump
hot and prime the injectors by lifting the air fuel plate up - either with 3mm allen
wrench inserted in the adjustment hole, or remove filterbox and lift plate up by hand.
When pump is running, you should hear a sqeal as fuel goes through injectors.  Don't
overdo it as you will flood the engine.  If there is resistance on lifting the plate,
then you may have clogged differential pressure regulator.

You should be able to verify spark - crank with primary coil lead connected to plug and
ground metal casing - I use a large alligator clip,  but somehow connect the spark plug
to ground.  You should see good healthy spark.  If so then see if spark is making it
through wires to the plugs - could just be a bad cap or rotor.

Compression would need to be very bad or almost non-existant if there is no running at
all.  That would be a broken timing belt or slipped crank pully - not usual.

You can revise what you said to be - air, fuel, spark, compression -all in the correct
amount at the proper time.  Then the engine will run correctly.

This engine is picky about having intake fully sealed  in order to draw in air and lift
the plate while cranking.

Comp. test is easy - as a precaution, ground out plug as above using center coil wire.
Cylinder by cylinder, screw in guage in place of plug. Crank engine using strong battery
- I usually have on charge while doing this.  Record and measure each cylinder reading -
twice for good measure.  Any low or incaonsistant readings may want to use some oil to
see if it is rings.  A little oil in the cyinder will seal rings and raise comp. for
that cyl.  If the engine has not been run in awhile, that may be all that is needed, as
a heat cycling of the engine may get things to seal up again.

Good luck.

Ben

Some troubleshooting tips here:  http://www.gtquattro.com/FAQ.html


[Date: Sat, 8 Jan 2011 13:07:28 -0500
From: Vincent Gelinas <vrgelinas at gmail.com>
Subject: Troubleshooting
To: "quattro at audifans.com" <quattro at audifans.com>
Message-ID:
	<AANLkTimk8Y3iKs7jvVVgc4ULD4EtAkNnyRqQbnZ53DgM at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Okay so I know the four things that an engine needs are fuel, air, spark,
and compression.  Engine is NG in 1989 90q.  I know I am getting fuel and
air.

I am going to be picking up a compression tester from Autozone in a few
days. The correct technique for using it that I have read is to pull my
ignition and fuel fuse, then crank engine over six times at wot with the
compression tester screwed into the spark plug hole.  Does this sound about
right?

Also, what is the best way to test my ignition system and what are other
things to look for? Any way to test hall sensors etc to see if I need a new
dizzy? That's the only part of the system I haven't replaced, besides the
possibility of the diode(?) on the coil mount bracket.

In good news, I will finally have a nice warm place to work on my car soon.
One of my friends has a horse barn that will be empty in a month or so and
said I can store and work on my car in there!

Thanks in advance everyone!

Vincent


------------------------------

Message: 5
Date: Sat, 8 Jan 2011 10:44:38 -0800 (PST)
From: Dan DiBiase <d_dibiase at yahoo.com>
Subject: Re: Troubleshooting
To: Vincent Gelinas <vrgelinas at gmail.com>,	"quattro at audifans.com"
	<quattro at audifans.com>
Message-ID: <282017.10744.qm at web39408.mail.mud.yahoo.com>
Content-Type: text/plain; charset=us-ascii

Vincent, you should do both dry and wet compression tests. Take a look at this 
write-up -

http://www.custompistols.com/cars/articles/compression.htm

I don't recall the exact issue you were having, but typically, loss of 
compression is evidenced by burning something that should
not be burned - oil or coolant. If you have blue or white/grey smoke coming out 
of the exhaust, you may have a compression issue.
I seem to recall that you've had trouble getting the car to actually run, so 
it's probably not a compression issue. But it's not a bad idea 

to check it out and compression gauges aren't expensive.

Glad you have an indoor place to work now too!

 Dan D
'04 A4 1.8Tq MT-6
Central NJ USA
]