New Throttle Body - slight differences to old one?

[GreatOldOne]

Hi guys,

I bought a spare 325 throttle body complete with TPS for my car. My current Throttle came with the car and is the same age as the rest of the engine ('86), so it has a throttle bypass screw on the top, two outlets on the right hand side for the 'airp pump' that feeds the vac lines to the brake servo, and no spigot on the bottom for any evap gear.

The new one is obviously from a later car - and it has no bypass screw (fine, no probs), the spigot on the bottom covered by a rubber bung in good condition, and only one outlet on the right hand side.

It's this that has me scratching my head. At first I thought the seller had forgotten to send the other pressed in metal elbow that goes in there, but looking closer shows that the outlet is not cut through to the bore of the throttle - it's just the casting on the side with the socket for the elbow.

I assume that this is normal for later cars - but how do I marry it up with the two vac lines I have? Is there a different bit of plumbing I need?

Thanks in advance,

Jason

[Rtaylor2208]

I had the same problem with a replacement TB and drilled through the second hole and attached it using the old pipes.

[GreatOldOne]

That was plan B

[Brianmoooore]

Drilling out the blocked port would be a very retrograde step. I often remove the stub pipe and block the port on older ones.
Get yourself a new large convoluted air pipe for a later 325, without the second branch to the brake servo valve, get a simple angled one way servo valve from a M40 engined car or a E34 or E36, and a couple of bits of vacuum hose, and just take a single pipe from the remaining throttle body stub to the one way valve, and then to the servo.
You'll appreciate the purpose of doing this if you ever want to remove the throttle body, TPS, inlet manifold, etc.

[GreatOldOne]

Thanks Brian - Of course, that means yet another new intake boot, as the new one I bought a week ago from cotswold has the branch for the 'air pump'...

What exactly does this pump do? it just seems to be several concentric tubes & orings when you take it apart.