Thread: D1 STEPPER MOTOR ON A D2 MANIFOLD

First off I would like to say thanks to BLKnight.au for his info on the 14cux
and especially his referals.

I read the artical by BritishV8.

This now begs me to ask the question, when installing a Thor manifold onto a 3.9 D1 engine and using the D1 fuel injection system 14cux. when connecting the 14cux stepper motor & housing to the thor manifold, PhilipA suggested to connect the main vacuum hose to the brass vac take off spiggot on top of the manifold.

However the article by BritishV8 on " Service and troubleshoot 14CUX Electronic Fuel Injection says the Bypass Air Valve vac hose should be connected to the plenum before the throttle body.

In PhilipA's advice to me, he said he used the vac spiggot on the bottom of the Thor manifold throttle body to hook up the rocker cover breather hose.

The question is, is it imperitive that the Bypass Air Valve (stepper motor)
be connected before the throttle body?

I run a Haltech E6 Engine management and not the 14CUX unit. The distributor is modified for the Haltech, no MAFE, other than that the system uses the same components as the 14CUX.

Incidently I also use a Haltech Stepper motor, a standard stepper can be used, but mine stuffed up so on advice from my engine tuner I fitted a Haltech Stepper motor ( that was 2 years ago and still functioning well)

Thank you Bee Uty. This is exactly what I thought.

I have made up a plate for the 3.9 stepper motor housing (where it bolts onto the D1 plenum) and corresponding to the open square hole I will fabricated a 1" spigot and plumb it into the 1" branch on top of the Thor.
A job for tomorrow.