Here's another intake from another angle. Find the rubber...

 

Please let me know if the airbox rubbers are the same as the ISV mounts. I'm compiling information for a massive update and third revision to my intake guide and this would be good to add.

 

No rubber to be seen on any of the 4 studs. The next photo shows all the hardware I took off these studs - just standard 10mm nuts and washers (no sprung washers on mine).

Dave just want to say thanks so much for putting together your instructions - couldn't do this job without them. It's testimony to them that they give confidence to a very inexperienced mechanic like me.

Have tried to follow the 'Chamberland Way'. Before I started put together a file with relevant write-ups, wsm pages, threads, PET pages. I'm also bagging and labelling hardware as it comes off. If I didn't it would be a nightmare remembering what goes where!

 

It has just occurred to me that if the rail mountings did use the same rubber studs as the airbox, then wouldn't the injectors end up not reaching the inlet? They would be at least 1cm higher because of the thickness of the rubber buffer?

 

My original question to you was in regard to the Idle Stabilizer mounts on the throttle body that originally started this topic of rubbers. Not the rubbers, mythical or otherwise, on the plenum casting for the fuel rails.

But, yes you are correct, use of the rubbers on the plenum to secure the rails would require that the casting be different and that is the case if my vague recollections are correct. We shall see. I have two low-VIN '87s close by that I can poke in the eye. I may have interesting pictures later today.

 

Dave..........the above post was what started the rubber discussion and considering Xolt "hasn't started his intake job" he is mistaken.

I have confirmed, as have you and Adrian, there are NO rubbers between the fuel rail and the intake manifold. Case closed.

ps......see response to your thread on V3

 

Definitely

 

Doh. Sorry Dave I missed the ISV bit of your post.

I'll measure the studs on each side of the ISV studs and see how they compare with the airbox ones.

 

Hi Dave,

Just measured the ISV mount and airbox rubber studs.

Looks like they're not exactly the same, but you could use the airbox ones in place if the original ISV studs sheared as mine did.

Both fittings have 8mm thickness rubber buffers.

The airbox studs have a long stud 14.8mm, short 7.8mm

The ISV studs are same length each side, 10.3mm

So the short airbox stud would fit into the throttle body thread. Poking around in there I think it woulod even work with the longer length (I think there's about 16mm of thread in throttle body).

I will get replacement airbox studs to use on the ISV and the distorted ones on airbox brackets.

Hope this info useful for your intake R&R revision.

 

I *think* the part from the '85 I mentioned is closer to 10mm in stud length. I do know for certain that the studs are the same length.

 

Looks like 85 stud is the way to go then. I see it's also $6 compared with $12 for airbox studs!

 

I've cleaned out the intake and am just putting back the side plates (the ones attached by 5mm allen bolts) with new gaskets.

Should I be putting any kind of grease on these gaskets or leave them dry, and what about the main gaskets which go between the inlet and the block?

 

Adrian................from what I've read dry seems the way to go but my OEM intake to cyl. head gskts look as if they had some 'dressing' on them from the factory.

Perhaps Dave knows for surity.

 

Thanks Malcolm. Dry it is unless Dave or someone else pronounces otherwise!

Been mostly cleaning today. The intake tracts clean up nicely with some brake cleaner, brush and a rag.

I put in a new flappy actuator. The old one was working but in comparison the new one works really smoothly and also seems a bit snappier for some reason.

Also took off the oil filler tube in preparation for new filler gasket. The clamps on the breather hoses attached to the rhs of the filler have to be removed to get access to the 10mm bolts holding it to the block, but it's very tight in there! I used a very small and thin 7mm wrench and turned the clamp bolts about 90 degrees at a time till I could remove the hoses.

While filler tube is off I have put on the cover from 928 Specialists.

Oh in the photos it looks like the knock sensors are in dreadful condition. In fact they were pretty good but have fallen apart as I've been cleaning vigorously in the vee! I didn't have to worry about this as I'm replacing them.

 

During the refresh I discovered that the 'vac valve' routing gas fumes to the carbon canister was not holding vacuum (the vac line from the valve goes to one of the connectors on the throttle body, so is disconnected when you lift the manifold).

You may want to check yours if you get gas fumes (as well as the notorious plastic Y-connector of course)

The vacuum valve is on the RHS. ON a UK car it's right under the brake master cylinder. Pic shows the new one in place.

The new one came today (928.107.307.00) from a local Porsche dealer, cost about $35 equivalent.

When I took out the old one I noticed it had VW/Audi markings! So may be useful to add to list of (cheaper) parts from this source. Next to the VW logo the p/n is 035 133 517.

When you apply vac to the new part you can hear it operate, but peering down the tubes gives no clue as to what's happening inside! Does anyone know what the actual mechanism is?