Investigation further - non start of ABY engine.

[Ben Swann]

Chris,

ABY, ADU, AAN ECUs are interchangeable AFAIK.  This engine is basically an AAN head on
re-worked 3B block with RS2/ADU intake and turbo - all set up identically to the ABY
engine I have on stand.  All sensors and ancilleries are identical to the AAN but in
different locations mainly due to different intake manifold.  I tested an RS2 ECU in AAN
S6 - worked fine and intend to use it once I have the engine running.  The main
difference in ECU internally is the chipset as well as some resistor, but otherwise
operates the same AFAIK.

The ABY harness is wired to plug and play in the Coupe Quattro, but I am finding there
are a few mismatches - although it is easier to wire than the AAN harness which needs to
be hacked up and refit with different connectors to work with the CQ wiring as well as
the different engine layout.

I have to admit, I'm stumped right now.  I know I'll figure it out, and have been in
similar situations on engine conversions before that use similar fuel pump trigger by
ECU based on Hall and flywheel sensors.  There only needs to be one wire wrong and
nothing works.

I tried "hotwiring' in place of the fuel pump relay, but that did not pan out.  I may
not have had all the connections right since it is difficult to tap into the wiring now
installed.

One thing I have not investigated is the alarm system wiring, but AFAIK, that will only
lockout the starter.  The engine cranks just fine.  Note - the starter wire is
integrated into the ABY harness, which is interesting.

Ben 

P.s if anyone on the A-fans lists knows differently on the ABY ECU, please advise -
AFAIK it is pretty much the same ECU as the AAN.

-----Original Message-----
From: Chris Semple [mailto:chris at force5auto.com] 
Sent: Tuesday, September 28, 2010 9:43 PM
To: Ben Swann
Subject: Re: Investigation further - non start of ABY engine.

Ben Swann wrote:
> AAN - same as S2/RS2. 
>   
Hmm, not sure on my end. The Rs2 is an ADU engine, the S2 is an ABY, neither p/n matches
an AAN engine ecu.
Do you have research to say this is plug n go? Is it possible the ABY harness is looking
for an ABY ecu?

-- 
-Chris Semple Force 5 Automotive 223 South Main St Concord, NH, 03301 603-223-6700
www.force5auto.com
>
> What ecu are you using?