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.
