1984 4k - no start

[Bares, Vittorio]

So yah - put the new ignition control module in - starts when it wants
to - doesn't seem to be any rhyme or reason - one thing that changed was
that it would get stuck in a high idle - pinch one of the vacuum lines
near the 6th injector and it would calm down.

 

As for the O2 sensor - err, uh - ETKA says it has one - I'd expect it to
be on the exhaust downpipe somewhere - but I don't see one - this is an
'84 - any ideas?

 

I'll move one of the additional battery to motor grounds to the firewall
(Huw, I think that is what you were intending when you mentioned that
the one to the motor is for the starter?) - read that in one of the old
'4k no start' threads from like 1998.

 

After O2 sensor, I guess it would be vacuum lines - looking for a
cracked one, then the fuel distributor (as suggested by Ben a few
threads ago) ?

 

Vittorio -

________________________________

From: Ben Swann [mailto:benswann at verizon.net] 
Sent: Monday, August 10, 2009 8:58 AM
To: Bares, Vittorio
Cc: quattro at audifans.com
Subject: RE: 1984 4k - no start

 

Vittorio, 

I would stop concentrating on spark and ignition for now.  The Hall test
checked out good.   As long as you have good Plugs,  wires, Cap/Rotor,
Coil and good connections, ground and charged battery then I'd suggest
problems lie elsewhere.

I don't recall hearing that you replace the O2 sensor - these will
indeed cause poor driveability when not working properly.

Ben 

[From: "Bares, Vittorio" <Vittorio.Bares at nuance.com> 
Subject: RE: 1984 4k - no start 
To: "Tony Hoffman" <auditony at gmail.com> 
Cc: quattro at audifans.com 
Message-ID: 
        <624BC75DA4460545849070E141EBCD6B0598CC17 at BN-EXCH01.nuance.com> 
Content-Type: text/plain;       charset="us-ascii" 

(possibly a 2nd send - sorry for dbl posting if it is) 

I added a 4g ground from the batt to the engine block. 
  
I also borrowed a known working coil from the same donor. 
  
I did get some spark although it was inconsistent, sometimes yellow,
sometimes white (on the tri-electrode plugs - should I see spark on all
3-electrodes simultaneously?).

How do I go about testing voltage at the coil - my Haynes is indicating
very specific procedures so as not to damage components - but they
didn't talk about measuring voltage at the coil - any procedures?

  
I'm wondering also if the ECU's might be different between these cars -
so tomorrow I'll re-run all my tests with: 

*       donor coil 

*       donor ign control 

*       original ECU and Altimeter 

*       jumped fuel pump 

 

What are the chances the distributor is faulty? 

Thanks for everyone's suggestions and help - I'm sure we'll get to the
bottom of this in time...]