Stepper housing leak ???

[willyribbs32]

I'm having quite a massive vacuum leak from this teet on the stepper housing and my idle when cold is pretty sporadic. could anyone shed some light on what exactly this is and where the missing line goes/where could I source one. or maybe if its just better to plug the leak?

[blaze_away]

Normally its blocked off, ie not used by TVR.

IF however you want to improve overall engine management run your ignition vacuum advance from this spigot.
You will get whays called "full vacuum" as opposed to normal ported vacuum where its connected on top of plenum just in front of the throttle butterfly.

Which ever you choose block the other one off.

And yes either being open will cause issues especially idle control

[Belle427]

Check to see you have a small rubber hose connected to your fuel regulator first as it looks as if something was connected there, may be blanked as suggested but worth checking.

[blaze_away]

Belle427 said:

Check to see you have a small rubber hose connected to your fuel regulator first as it looks as if something was connected there, may be blanked as suggested but worth checking.

Good call, I forgot that.

[blitzracing]

That's the fuel pressure regulator take off. It must be connected to get the fuelling correct.

[Steve_D]

blitzracing said:

That's the fuel pressure regulator take off. It must be connected to get the fuelling correct.

Pressure regulator takeoff is normally low down on the back of the housing (and a complete pain to get at on a Chim/Griff.

Not sure I have see a takeoff in that position before but there could be other housing versions.
On a 3.5 the takeoff is actually in the inlet manifold rather than the stepper housing.

Steve

[lancepar]

I found a photo..

.

[blitzracing]

Steve_D said:

Pressure regulator takeoff is normally low down on the back of the housing (and a complete pain to get at on a Chim/Griff.

Not sure I have see a takeoff in that position before but there could be other housing versions.
On a 3.5 the takeoff is actually in the inlet manifold rather than the stepper housing.

Steve

How right you are. Not spending enough time staring at my engine lovingly obviously . I only have the one take off below the stepper for the FPR.