The Manhattan Project

[AndrewSlater]

Thanks for the input Tim.

I have a set of new injectors still in their boxes and didn't want to damage them.
I also have the old rusty ones - so will try again with injectors once I have rebuilt my FD again.

Should I be able to get zero flow from the injector lines with the air plate in the closed position?
I have cleaned and rebuilt everything so the hex screw adjustment is likely to be wrong so maybe the plunger can't fall far enough to close the injector feeds fully.

[AndrewSlater]

Getting my CIS into a known good state has eluded me so far - so another weekend and another attempt to get to the bottom of the problems.

Since last weekend I had rebuilt the fuel distributor again ( I think that is the third time ) but again couldn't spot any issues.
I then worked out that my fuel pressure gauge wasn't working correctly - the quick fit connection wasn't allowing any flow to the meter head - that would account for some of the issues.

We started to re-run the tests from the beginning again but now failed at the first hurdle.
The fuel pump was putting out quite a derisory flow rate, much much lower than last weekend.
After a lot of head scratching I eventually found that the non return valve in the fuel pump banjo had decided to call it a day and mainly block the outlet.

At this point I was starting to think the CIS was jinxed!
Luckily I had another pump and borrowed the non return valve - all good flows again.

Now we had pressure in the system, although one of the injectors was permanently flowing.
The system pressure was 4.5 bar with the WUR disconnected with the tap in the test setup. This is just about at the bottom of the spec.
The injector symptom pointed at the FD still being broken, so we decided to concentrate on testing the WUR.
With the tap moved to allow the WUR in circuit the pressure dropped to approx. 0.2 bar - so much less than the 1.2-1.5 I was hoping for when cold.

I decided to use the method of hammering the centre pin on the WUR from the inside to get the pressure up.
After a few attempts we were at 1.2 bar cold which was a big improvement.

To test the hot setting the WUR was energised for 10 minutes and a hot air gun used to persuade the WUR to heat a little more.
We soon had the WUR in circuit and the control pressure sitting at 3.0 bar - result.

Now that I was relatively happy that the WUR was running pretty well, it was time to strip the FD down again.

This time I fully stripped the unit and found another broken o-ring ( on the circuit that was causing the injector to continuously flow )


So even the O-rings provided in the Salvox kit are delicate.
Using a new o-ring I had spare from the first time I rebuilt the FD, it was all reassembled for the fourth time!

And this time none of the injectors ran until I moved the air-plate - result!

Whilst I had the test setup together I confirmed the following:

the Fuel Accumulator holds 2.0bar system pressure after the pump is stopped.
the cold start valve can be actuated and doesn't weep.
and finally I ran an injector balance check, to see that all the injectors are giving out comparable flow rates.

So finally all the CIS components seem to behaving as I was expecting.

I carefully removed the pressure gauge test setup and returned the CIS to standard.
I decided to carefully torque all the fuel line connections just to make sure nothing would leak in future - better to be safe than sorry.

As I got to the last banjo - snap !!!


Grrr! - as I said jinxed !

Oh well hopefully on the home stretch with all this.

[Bruce M]

Looks like you are the resident CIS expert now

[Gary71]

Looks like you are the resident CIS expert now

When you get to the point when no one answers any question you have exceeded everyone else's knowledge level!

You are on your own...

[AndrewSlater]

You are on your own...

Eeek!

[jb]

You have probably accessed these links already but they provide a lot of useful info on CIS

http://forums.pelicanparts.com/porsche- ... mmies.html


http://jimsbasementworkshop.com/CIS/CIShome.html

[AndrewSlater]

You have probably accessed these links already but they provide a lot of useful info on CIS

Yes thanks for the info - much appreciated.
I've spent a lot of time in Jim's basement this summer - which probably explains the pale complexion.

[AndrewSlater]

Had some good news from Mike B, my gearbox is now ready.

He has sent me the obligatory photos so I now need to hatch a plan to repatriate it over Christmas.







The parts list ran to;

1X pinion nut
1X input shaft nut
2X syncro bands for 1st/2nd
3X syncro bands for 3rd/4th/5th
2X diff bearings
1X large pinion roller bearing
1X diff case input shaft bearing
1X O/S Time-Surt M12XM8
1X new throttle shaft
2X gear bearings

Plus the 'new' fourth gears I sourced to replace the worn ones.

Like Jamie I got the football, but luckily a '4' instead of the 'arse' 4=0

Can't wait to mate it to the freshly rebuilt engine.

Just need my shell to be returned painted next!

[Lightweight_911]

Another step closer ...

[Gary71]

Looks good, having a nice crisp gearbox makes all the difference.

[AndrewSlater]

....'it's starting to look a lot like Christmas'....

[Gary71]

Loving it!

[Lightweight_911]

Looks fabulous !

[inaglasshouse]

Fab. And a great thread, thanks for posting.

[Dougieboy1]

am very jealous. I am miles away from this point....

you will have a great christmas from the look of it and jove the colour!