No Start : 3B.TIMING & ECU Q's

[Ben Swann]

Stan,

That the car stopped in traffic gives us a bit more info. to help you.  Recap on problem
and suggestions in prior emails below.

First off - don't start by throwing money at the problem.  Do some methodical
trouble-shooting and you'll nail down the problem.  Try to do as much as you can before
throwing in the towel and spending a lot at a mechanic.

Try what I suggested below - verify timing belt is correct, distributor/hall adjusted
properly.  Most of this can be done with very few tools - for example, the engine can be
turned over by pushing back and fourth in higher gear - third is good.

Keep the top part of timing belt cover off until you have this figured out.

If it is not the coil, then some things that can be the problem:

Ignition key - sometimes they fail to provide power to ignition portion - the switch has
2 or 3 connections to various subsystems in the car, so lights may be on, and engine
cranks, but the ignition circuit could be failing.  This can be intermeittant and hard
to track down.

Hall signal is going out of window.  This can even be cause by belt slop - I have seen
cars start when cold, but not when hot and vice versa since the hall is not adjusted in
the middle but off to the side.  So the contracting of the belt moves the cam a bit and
throws the distributor off.  I have seen this in 3 cars and I'm not a mechanic by trade,
so that is high percentage.

Anyway - you need to have both flywheel sensor signals and hall signal in the correct
syncronized order for there to be ignition primary ( and fuel pump trigger).  If you are
missing any signal, or it is not at the proper time, then you have a no start.

Is there a way for you to pull codes - that really helps to find the problem much
quicker.  You are more or less shooting in the dark without a code scanner.  Maybe
someone has one around, or you can find a local mechanic who won't gouge you to read the
codes.

If you lost a flywheel pin, then the car will not get the crank TDC ref. signal. No
Start.

Keep track of trouble-shooting steps so you can at least give a rundown to the lister
willing to help.

Ben


[From: Stan Evans(stanevans3 at gmail.com)

Subject: Re: Thank you for Quattro123.com...do you know anyone in the Philly So NJ area

Hey Steve:

Thanks for taking the time to send me the email.

Actually, the car suddenly died on me 90 miles from home and had to be towed, which was
the beginning of the discovery/learning process.

It appears that the only way to check the ECU is to plug it into another 91 Audi 200 20v
to see if it starts. I found a used ECU for sale at Shokan for $800 and another one at
Force5 for $350. Being laid-off and tight on cash, I can't just throw money at something
to HOPE that is the problem.

That is why I am hoping I can plug my ECU into a functioning 20v to see if it works or
not. Any thoughts?

I really appreciate everyone's help with this.

Thanks,

Stan ]  
________________________________

From: Ben Swann [mailto:benswann at verizon.net] 
Sent: Tuesday, March 09, 2010 3:08 PM
To: 'Ben Swann'; stanevans3 at gmail.com
Subject: RE: Scott sent me!
Stan,

Steve Mills mentioned the next thing that came to my mind.  If you have everything else
correct, but the wires are off, the car will produce spark, but not start. 
 
You need to first go back and double, triple check timing belt is proper.  Do not rely
on dimple on front belt cover - verify TDC using the flywheel mark.  I often need to put
a rod down #1 spark hole and turn engine by hand until the rod is at it highest point -
then the mark should appear and you can mark the harmonic balancer if it indeed slipped.
If you can get someone to help, that will speed things up immensly.
 
Once you validate TDC is DEAD ON - I repeat DEAD ON.. then you can get the timing belt
adjusted properly.  Once you have timing belt/water pump locked down, then verify hall
window is exactly in the middle of window - per BENTLEY manual.  If you need
clarification on this let me know.
 
Once you have all these things properly verified and lined up and wires in correct
position, then the car should fire right up.  If you hear the fuel pump kick, then the
engine is trying to make spark.  No fuel pump sound means no primary ignition pulse - go
back to square one.
 
If you hear the pump, but no start, then check wire position.  Wires out of position
will not gen a code.
 
My tip to checking ignition starts with taking the coil wire off the cap and attaching a
spark plug and grounding the casing using a large alligator clip or jumper cable or vice
grips.  You can then see all five sparks if they are being produced.
 
HTH
 
Ben

________________________________

From: Ben Swann [mailto:benswann at verizon.net] 
Sent: Tuesday, March 09, 2010 2:55 PM
To: stanevans3 at gmail.com
Cc: 'Ben Swann'
Subject: Scott sent me!

[SnIP]

What codes came up on the no start?  If no codes, then may be a bad coil.  A bad ECU
would not have registered with  VAG-COM or whatever scanner you used, or would have
reported many codes that don't make sense or possibly just faulty ECU.  If ECU was
talking to VAG-COM and no codes came up,  then most likely you have a bad ignition coil.

I'll need more specific details of what is going on.  We can try swapping ECU, but it
does not sound like the problem - not unless there is some info. that points to it. I
re-read the post and says you tried the coil.

Need more info!   Best I can ascertain the last thing you did was replae the timing belt
or make related adjustments.  The hall distributor could be out of window, but that
should have thrown a code.

Ben 

[From: Stan Evans <stanevans3 at gmail.com> 
To: SuffolkD at aol.com 
Sent: Tue, Mar 9, 2010 9:04 am 
Subject: Thank you for Quattro123.com...do you know anyone in the Philly So NJ  area 

   Hi: 

My name is Stan Evans and I have a 91 Audi 200 20v that I picked up last year.? This is
my sixth Audi (3 different '90 200 Qs, 90 Coupe Q, 93 Audi CS Wagon) and now finally a
200 20v. 

First of all, THANK YOU so much for the valuable info on your site.? I was able to
change the timing belts (it was off TDC), double check the distributor, replaced the
original fuel pump, replaced the starter, and learning about the ECU.


Here is the situation...the Audi is not producing any spark from the Ignition Coil.? I
have ran the codes, ran the other basic checks from the combination of your site,
Bentley's Manuals, and http://www.sjmautotechnik.com/ <http://www.sjmautotechnik.com/>
.? At one point I did get spark from the ignition.? A couple days went by and I tried
again and then no spark.? UGH!? I ran some of the tests on the ignition and supposedly
according to Bentley's the ignition coil was bad.? Simple replace and nothing.? !@$%^

Anyway, I thought that before I spend money to see if it is the ECU, I could see if
there are any local owners of 91 Audi 200 20v Q that I could quickly have us either plug
my ECU into their car to see if it starts, or plug their's into my car.? The ECU in my
car appears to have been accessed at some point.? There is no plastic baggy around it,
and someone wrote a name on the underneath the ECU.

So do you know of anyone local I could perform this quick and simple test with?? If not,
could I send my ECU up to you and the other guys at Quattro123 to see if you can plug my
ECU into one of your cars?

I have been driving around in my clunker Jeep and I think the tranny is about to go in
it.? I really appreciate your help with this.

-- 
Best regards, 
Stan Evans 
310-403-5774]