Dived right in

[Daviboy]

Now been home a full week and after driving the car a few days and tweaking the idle, have not done much. Decided after hours of staring and prevaricating that the air box which needs replaced was coming out. So in anticipation of this I took a few pics prior to starting the job. This am I spent about 2 1/2 hrs tearing down the injector head, air intake boot, removed the throttle linkage and a bunch of suspect vacumm hosing. Removed the injector lines and unbolted the intake runners. The top of my air box literally came out in my hand once I got the mount etc out the way so badly blown was it, but car still drove. I have some sore knuckles but almost 3/4 of the crap out that I need to take out so stay tuned, will post pics later, now got semi clean hands and a list from the wife.

[Daviboy]

Have posted some pics on flickr tonight. I got the intake runners, airbox, vacumm hoses re-installed today. The airbox mounts are easy enough. The rear of the airbox presents a few challenging words but it is all do-able without dropping the engine, take the big rubber boot off first is the trick. Got throttle linkage cleaned and re-greased, that spring which goes to the underside of the middle left runner is a b****r. Anyway tomorrow will see the throttle box, fuel dist/air valve, finish hooking up vacumm hoses should be running by this time tomorrow.
Plenty pics here http://www.flickr.com/photos/30575902@N03/

[Daviboy]

The beast is running very rich but she is running. Guess because there was so much unmetered air getting past the airbox the PO just richened it up to keep it running, the intake valves are a bit brown I think which indicates rich condition. Will lean here out big time before starting again, there was so much fuel coming through the motor it was coming out the exhaust in a mist. The timing I think it way off, when I shine a timing light in before doing the airbox the marks were showing at about 4 oclock looking down on the lower pulley. Anyway thats another story.

[mca]

Great photos.

So you managed to get the CIS out without dropping the engine! That is a tall order!

I frequently see 911s with cardboard under the engine while parked in the garage. Does it leak oil?

One word of caution ... if you didn't install a pop-off valve, you should probably do so. Especially if you are messing with the mixture settings. One backfire on startup could blow that box up!

[Daviboy]

mca,
Its not easy but is do-able just have to think like a german to do it..... Anyway no big issue. Yes my 911 does leak but only when cooling down and not as much as my old Disco. I just the cardboard in case but in two months about 12 drips... go figure... New box has pop off valve as well

[mca]

Ya ... I was just kidding about the leak. Hence the wink.

Nice work and thanks for documenting!

[Daviboy]

mca not so anal I cannot recognise a joke, I am Scottish so.... lots of jokes about us but we are still here being innovative

[Daviboy]

Motor running rich but running

[steely]

Nice job Davy. I've been saving and spending my pennies on small parts in order to replace some of the older bits as we get closer to winter here. But I haven't decided to take the plunge and do the deed yet as our weather has been pretty mild.

I make small orders and then make sure I get home first in order to get the box in the garage before "anybody" else does - I don't need any more lists either - ha ha.

Thanks for the pics - it's encouraging.

[Daviboy]

Car is running fine I adjusted the timing and it is now spot on 5 btdc +/- 900 rpm I reset the idle this morning after a run up to op temp. Have found if I set idle at 900 have a run then come back and check idle is around 1000 - 1050 rpm so do it when hot. The car is a different machine now that she is breathing properly, solid power from around 1500 rpm shift into 2 2750 rpm lots of low end grunt (I felt that wee targa twist a bit today) shift into 3 at 3500 rpm and plant your foot smooth steady power all the way awesome. Maybe it is time to get an anti sway bar fitted thats a lot of torque through an old chassis....

[Paulporsche]

Daviboy,

Good work and nice writeup.

Why did you replace the box rather than repair it?

Did you replace anything @ the same time?

I sent you 2 PMs. Read the longer one.

[Daviboy]

Paul,
Further to PM I sent you earlier I have still got the old airbox which I am going to repair. Reason I went for a new one was for peace of mind. If I can adequately fix the old I will keep as a a spare. It has been done before I think Iceman on here did it. Anyway as I said it wil be as a spare if I can make a good enough repair.

[targabill]

Quick question, can you lift out the Airbox with everything fuel related attached, runners, fuel distributor, and even the solid fuel lines (left Connected to the distributor and injectors??

Thanks much,
Bill

[boyt911sc]

Originally Posted by targabill

Quick question, can you lift out the Airbox with everything fuel related attached, runners, fuel distributor, and even the solid fuel lines (left Connected to the distributor and injectors??

Thanks much,
Bill

YES. But it would be more difficult to remove the complete CIS unit in situ. And installing the CIS unit back in is another story. If you have not done this before and have limited experience why make your life more miserable? You need more than 4 hands to install the complete CIS as a single unit with the engine in place. Good luck.

Tony

[fanaudical]

I've done this both engine in and engine out of the car. Removing the CIS with engine in the car requires a partial engine drop anyway. Every time I've done this with the engine in the car I have found myself wishing I had just dropped the engine...