Another turbo conversion comes to life

[Ti Kan]

Todd Phenneger wrote:
>I will support both of Huw's statement.  If you need I can go
>outside and check my Kh but the the wire that goes to circuit BS
>will indeed make your MC/KH fuel pump relay work properly.  I
>just spliced mine in.  Works great.
>  My overboost FPR Cutoff has NEVER worked on 4ktq conversion
>though, and my Fuel Pump runs all the time when the ignition is
>on.  I'm curious if you have the same problem after you finish
>your conversion.  If you do I want to compare wiring notes.

Todd,

If your FP relay runs all the time as soon as the ignition key is
turned on, and the overboost cutout doesn't work, then I'd say
either the FP relay is not wired up correctly, or you're using the
wrong relay.

Eric writes:
> I don't have an MC or KH FPR handy, but I did notice they have more
> contacts than the JT/4k FPR.  I am going to order a KH unit.  Strangly
> it is about half the price of a JT unit.  I will let you know the outcome.

Eric,

The reason why the KH FP relay is cheaper is probably because it
actually has less electronics in it.  On the JT (and other non-turbo
CIS/CIS-E Audi cars of the era), the fuel pump relay gets a signal
from the ignition coil, and has circuitry to turn on the fuel pump only
in the presence of ignition pulses.  This is for safety reasons
(so that the fuel pump shuts off when the ignition stops).  On the
KH (and MC) engines, the engine ECU controls fuel *and* ignition so
it "knows" whether there are ignition pulses or not, and therefore
the associated FP relay does not need the pulse-detection logic.

-Ti
2003 A4 1.8T multitronic
2001 S4 biturbo 6-sp
1984 5000S turbo
1980 4000 2.0 5-sp
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    ///  Ti Kan                Vorsprung durch Technik
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