Alfa 75 Ignition set up

[David Masters <david@xxxxxxxxxxxxxxxx>]

On  Date: Wed, 2 Apr 2003 16:33:56 +0100 
Miguel Pereira Trindade <mptrindade@domain.elided> wrote:

> Subject: Alfa 75 injection set-up
> 
> Hi there Gang,
> 
> I have a 1991, Alfa 75 2.0 TS, 110.000 kms
Mine is 2 years earlier.
  
> After passing the 100.000 kms it's fuel average raised dramatically, up to
> 19 lts/kms at top speed and 14lts/100 kms at economic speeds.  This was a
> dramatic change from previous averages of 12.5lts/100kms and 7.5lts/100kms
> respectively.

I experienced similar problems. Nothing specific was found, but I
did my usual service of the earth connections, the battery
connectors, washed the Idle speed stabiliser, cleaned the intake
manifold, and swapped the Oxy sensor for another second hand
one. Cleaned all the connectors on the sensors with "contact
cleaner".  The particular concer is the temp sensor at the back
of the head.
  
> We already cleaned injectors, verified fuel pressure valve,
> checked if both sparks are working ok, we cleaned injectors, the consummations
> are better,
> 14lts/100kms at top speed and 11 lts/100kms economic average. But we can't
> get any better than this!

Yes, that was where I started too.  IMHO the injectors usually
just need fool injector cleaner every 10K kms.
Both my rotors have failed in the last 2 years.  Be very sure
that you are getting spark to all plugs.  Again, a simple thing.

Look for the simple things....keep reading below....
  
> I thought about checking if injectors are working properly, but I do not
> have the parameters of them... does any one as the technical data for the
> injection system?? Data of what emissions should be throughout the revs
> spectrum?? Etc... Or any ideas where I should look into... I would
> appreciate very much.

Put your finger on it.  If it ticks, it is working.
Again, not a common point of failure.
My problem ended up being vacuum leaks. The hard plastic tunbes
that go to the canister at the front of the car use standard
rubber vacuum tube as the connector.  All of mine have perished. 
Various leaks at all the joins were contibuting to the problem.  
Change them all at once, as I found that after changing one, there would be
another one leaking months later.

Obviously this may not be your problm, but nothing strange has
ever gone wong with this Motronic system.  Some people blame the
"computer" for every malfunction, however I always look for
faulty sensors.

  Cheers,
  david
  1989 Alfa75 Twin Spark, 180000kms. 
  
> By the way can anyone help me where I can get some larger disc
> brakes and
> callipers, to use with some 1644  wheels for track day use?
> Because the
> Tar-OX 42 grooved discs are not enough at Estoril track, just
> after 20 min
> into the sessions they start to fade heavily. By the end of the
> sessions
> they smoke dark fumes...
> 
> 
> Cheers
> MIG
> "May the Force be with you!"
> 
> 
> PS - I intend to use this car just for track days, but I still
> haven't
> changed anything on the engine, besides putting a KN air filter.
-- 
David Masters, Group Leader - UNIX, 
BHP Information Technology, Newcastle, AUSTRALIA.
Internet: david@domain.elided        	     Phone: 049 402132
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