CIS pipe connection

westyguesty · 03-25-2013, 04:17 AM

I have just put my engine back in to my 1980 911sc after replacing broken studs etc, and I think everything has gone OK (the truth will be when I start it next week).

All my labels for wires and breathers held OK, excepts for one breather pipe. It's from the CIS body, an feels / looks like the top pipe. I have the one on the distributor, two on warm up regulator and the three on the on the other valve (can't remember it's name

).

The one I can't find a connect for is slight longer than the one to the distributor.

I have search through the forums, but can't find where it goes, can anyone help.

Thanks

scotricker · 03-25-2013, 04:26 AM

I'm not sure what you're showing in your pic. Is that the top throttle linkage? Just for a point of reference, where are we looking?

T77911S · 03-25-2013, 04:34 AM

you need to show more/better pics than that and/or explain what you have way better than you did.

westyguesty · 03-25-2013, 04:57 AM

Sorry for the poor picture, engine back in car, so picture was a bit difficult.

Looking from the back of the car, it is the rear left side / corner of the throttle body. You are right, you can see the throttle linkage and spring in front of it. The top pipe you can see if the one i'm struggling with.

boyt911sc · boyt911sc's Garage

Is the car/engine a US model or RoW? Could you take pictures of the engine? Not all the nipples/connections on the throttle body are utilized. Some are plugged. Keep us posted.

Tony

westyguesty · 03-25-2013, 08:33 AM

Yes, its row, 204bhp 1980 model. Fairly low miles, I'm the second owner and knew the first. The engine has never been out before, or anything really disturbed. Looking at the end of the pipe it looks like it was connected. I have seen a few posts with people having two connections to the distributor, but I can see only one on mine.
I will go through some of the pictures I took and post a few.

Vereeken · 03-25-2013, 11:07 AM

You have 2 vac connections on the back of the TB. One above throttle buttelfly one below.

One line goes to the distributor.
The other goes to the vacuum side of the WUR Type 089. If you still have the decel valve and thermal valve it will go from the TB first to the decel valve next to the thermal valve and then on to the vacuum side of the 089 type WUR.

I always confuse them both but there is an easy test. Attach the two hoses to the back of the TB. With the engine idling at 1000 rpm you should feel suction on one line and no suction on the other. Put it on your tongue for the final test

)
If a helper revs the engine you will feel that one line has always the same amount of suction the other the suction will increase with the revs.

The line with no suction (or increased sutcion with rising revs) at idle goes to the distributor (you should have a euro spec dizzy with only vac advance).

The line with constant suction goes to the side of the WUR (passing decel and thermal valve first if you still have them in place.)

A small note if you still have the thermal valve you will feel no suction whatsoever for the first 50 seconds (the time it takes for the thermal valve to open). That is ofcourse assuming that the thermal valve still is fed with 12v.

Michel