CIS injection sequence

[beepbeep]

Ah, great!

How did the leak reduction project go?

[Alan L]

Not very well - have plugged all the do-able leaks.
But still cannot hold a static test pressure. Those leaks are not really fix-able; leaks at the idle screw, butterfly shaft - neither of which are O ring sealed, and at the aluminium Y piece that pushes into the inlet manifold block. I say pushes in, because that is all it is - a piece of Al tube pushed into the manifold.
Have tried to seal it - don't know how sucessful yet. The injector blocks are well sealed now. Hopefully I have all the big leaks, but it seems impossible to deal to some of the smaller ones.
But it must be better than it was. Will find out soon.
In the next week or two, I think I'm actually going to get to drive the thing.
Regards
Alan

[Alan L]

Originally Posted by Alan L

After 'idling ' -as best you can on 3, for about 30 secs, the headers on LHS are too hot to touch. The headers on RHS are stone cold, with one luke warm.
Alan

Just for the sake of explanation here - I think what was happening is that with limited fuel supply/pressure, the fuel was going to the injectors with lowest opening pressure. It would only need to be 1 psi or so lower. So, the lowest 3 just happened to be on the LHS, with another (#6) very close to same- and received fuel occaisionally. #'s 4 &5 must have had highest opening pressures.
Alan

[beepbeep]

Originally Posted by Alan L

Not very well - have plugged all the do-able leaks.
But still cannot hold a static test pressure. Those leaks are not really fix-able; leaks at the idle screw, butterfly shaft - neither of which are O ring sealed, and at the aluminium Y piece that pushes into the inlet manifold block. I say pushes in, because that is all it is - a piece of Al tube pushed into the manifold.
Have tried to seal it - don't know how sucessful yet. The injector blocks are well sealed now. Hopefully I have all the big leaks, but it seems impossible to deal to some of the smaller ones.
But it must be better than it was. Will find out soon.
In the next week or two, I think I'm actually going to get to drive the thing.
Regards
Alan

Yeah. It's the big leaks that mess up the engine. Turbocharger has ample air capacity so small leaks (around butterfly shaft etc.) are manegable but if they add up you will have noticeable power loss. Which Y-piece are we taling about btw? A drop of epoxy around edges can probably seal it well.

I'm sure you'll feel great difference once you start driving the car!

[WERK I]

Originally Posted by Alan L

Except I have not touched the cam timing - I've just had everything off down to the long block........
Alan

Sorry for asking a stupid question..........

Did you move/remove the distributor from the engine?

[Alan L]

Dave, not a stupid Q - but I did not remove it. I did remove the clip, and feed , or trigger wire that goes into the base of it.
I have re checked the timing.
Goran, the Y piece is an Aluminium tube that sits almost below the BOV - plugged into the intake manifold. I found a bit of a leak coming from there, then found it could move (twist). Looked at it some more, and figured you can't unscrew it - one leg is too long to clear the manifold. So, wiggled it a bit and it came straight out in my hand. I was a bit surprised at this bit of Porsche design - considering it takes up to 14 psi boost pressure as a fitting.
I have reinserted with loctite and crossed my fingers it does not blow out under boost - or the car will definitely come to a stop.
Regards
Alan

[RarlyL8]

That Y-fitting is frozen in place on my manifold. I tried to remove it when all the smog stuff was yanked and gave up for fear of damaging something. Yours must have worked loose somehow.

[Alan L]

Brian, I hope mine is now frozen in place too - but want to give the super stud lock stuff time to full strengthen before I attempt yanking on it.
I am surprised Porsche could not come up with a better option - eg a screw down O ring flange or similar.
Seems very crude for a part that works under some load.
Regards
Alan