[Diy_efi] Audi EFI conversion?

[Bill Shaw]

There are some gains to be had by deleteing the airflow restriction
presented by the fuel distributor.  Learning to tweak a K-jet system is like
learing to make sealing wax.  Might be an interesting excersize,  but
somewhat acedemic since it is an ancient, obsolete system.

Yep,  Bosch sold a lot of them,  and they are pretty good considering the
state of the art when they were designed,  but better fuel economy and power
can be had with a more modern control system on the same engine.

The fact that Ferrari was one of the last manufacturers with k-jet in
production says something about how well they worked.  Yet even Ferrari has
moved on to contemporary electronics to gain better control of the engine.

MHO,

Bill

> From: Torbj?rn Forsman <torbjorn.forsman at gengas.nu>
> 
> The K-jetronic systems of Audi normally work very well and reliably.
> In case of more recent ones, labeled KE-jetronic, there is an ECU that
> controls the fuel flow via an electromagnetic valve (usually called EHA,
> electrohydraulic actuator) in the fuel distributor. This ECU may be
> either an analog one (similar to the Bosch LE and LU-jetronic systems,
> built with a bunch of quad op amps and possibly a hybrid circuit for the
> lambda integrator) or a microprocessor based one, with typically an
> Intel 8051 or 80535 CPU. In some cases, the same ECU also controls the
> ignition timing and then the system is labeled KE-motronic.
> 
> I think it would be wasted work to replace the K (or KE) system with an
> all-electronic one. It is much more fun to learn tweaking the K-jetronic
> system for one's own needs!
> 
> Similar systems are used on many other european cars from the 80's, for
> example Saab, Volvo, Volkswagen, european Ford, Mercedes, Porsche.
> 
> /Torbj?rn Forsman
> 
> 
> Bill Shaw wrote:
>>> Bill, that was quite a thread on the Ferrari chat re MegaSquirt, did anybody
>>> ever try it?  
>> 
>> 
>> I don't know of anyone that tried Megasuirt on a Ferrari.  They seem to be
>> at opposite ends of the spectrum,  cheap engine controller and expensive
>> exotic cars.  I've seen Motec and other top $ controllers on Ferraris but
>> not MS.  Doesn't mean it hasn't happened,  I just haven't seen it.
>> 
>> 
>>> Same problem of long CIS injector reach on the Audi, so you've
>>> given me something to look into, for sure.  Nice that the Audi manifolds are
>>> threaded for a brass insert into which the CIS injectors are pressed.
>> 
>> 
>> Yes,  same threaded inserts in my recently departed '81 928 and the k-jet
>> Ferrari V8s.
>> 
>> I don't know what the Audi intake looks like,  but I was looking at the 308
>> intake runners when I had them off a while ago,  thinking about upgrading
>> from k-jet so I could add some boost.  I haven't done a detailed analysis
>> yet,  but I was thinking that I might be able to fill the existing injector
>> hole and machine a flat and a bung down lower on the runner to accept a
>> newer GM style injector,  like on my Z28 LT1.
>> 
>> Bill
>> 
>> 
>>> Ernie B.
>>> 
>>> 
>>> ----- Original Message -----
>>> From: "Bill Shaw" <b.shaw at comcast.net>
>>> 
>>> 
>>>> Hey Ernie,
>>>> 
>>>> The CIS injectors are quite different from the efi injectors.  There is a
>>>> company that makes an adaptor to convert CIS to EFI bitzracing.com,  but
>>>> the
>>>> efficacy depends on the design of the CIS system.  It is basically a bung
>>>> to
>>>> replace your CIS bung that is machined to take the efi injector.  Unscrew
>>>> the CIS injector retainer,  screw in the adapter,  install the new
>>>> injectors, and build up the rest of the fuel system.
>>>> 
>>>> http://www.bitzracing.com/products/injector_bungs/injectorbungsdetails.html
>>>> 
>>>> It looks like it would work well on my Porsche 928 (I've owned both CIS &
>>>> EFI 928s) but might not work so well on my Ferrari,  reference the
>>>> following
>>>> thread on FerrariChat:
>>>> 
>>>> http://www.ferrarichat.com/forum/showthread.php?t=76848
>>>> 
>>>> Once the fuel side is settled,  you need to work out the sparky side of
>>>> things.  Megasquirt is one possibility,  but only controls the fuel.
>>>> Junkyard EFI is another.  I've had pretty good luck with the '749
>>>> controlling both spark & fuel,  others have done well with different GM
>>>> ECMs.  If you're EFI'ing the turbo Audi the 749 is worth a close look.
>>>> 
>>>> Bill
>>>> '84 928s 5 sp. Vortech/749
>>>> http://p-928.home.comcast.net/749.html
>>>> 
>>>> 
>>>>> From: "Ernest Buckler" <ebuckler at icehouse.net>
>>>>> 
>>>>> Ernie here, long time lurker, owner of EFI motorcycles and a couple of
>>>>> Audis
>>>>> ('86 5000, and '89 200 Turbo 2wd) that I'm thinking really need EFI to
>>>>> replace the messy K-Jetronic constant-flow stuff.  I have a small machine
>>>>> &
>>>>> welding shop, thus can make brackets, drill  & tap ports and holes, etc.
>>>>> I'd really like to be able to build a fuel map on a PC, datalog, etc.,
>>>>> even
>>>>> tho I know v. little about the process - but figure I've gotta start
>>>>> somewhere, eh?
>>>>> 
>>>>> Without a Search Engine for group archives, I'm lost; can anyone direct
>>>>> me
>>>>> to info on converting an Audi CIS system to EFI, if anyone has done this?
>>>>> The inspiration for this hypothetical project derives from noticing that
>>>>> the
>>>>> O-ring kit for Audi CIS injectors also was spec'd for a whole long list
>>>>> of
>>>>> true EFI vehicles as well - meaning that one of these EFI injectors (to
>>>>> be
>>>>> selected) should plug right in to the Audi ports...?   I'd need to make a
>>>>> fuel rail,  adapt a TPI and some sort of air flow measurement hardware,
>>>>> plus
>>>>> adapt the Audi temp sensors to the new ECU, also to be selected per
>>>>> suggestions.
>>>>> 
>>>>> Thanks in advance,
>>>>> Ernie B.
>> 
>> 
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