I removed the copper plated fuel injector lines from the engine because I was not confident that they were clean, and I flushed each one inside with hydrochloric acid (HCl) using a syringe to flush it back and forth. Lots of rust, particulates and rusty coloured fluid came out at first, and then rinsed with water, and flushed again with HCl, repeating until the acid ran almost clear. Then I flushed with water, and then WD40, and then with STP fuel system concentrated cleaner, and finally with MolySlip Combat. They are as clean as they are likely to get so I reinstalled them after all this, and cleaned the injector attachment and delivery valve attachment too. I think this is the key for anyone with a 404 or 504 injection - make REALLY sure the inside of the lines are clear if the car has not been used for a long time, or if the lines have not been on the car at all for some years.
Some of the stuff that came out of the injector lines when they were flushed!
You can see here the colour - dark orange - of the HCl inside the clear vinyl tube!
After cleaning, they were re-mounted on the engine.
I got a new tube for the radiator overflow, and then installed it in the car.
My Hydrovac was bought NOS in 1993 and was installed in the car around 1998 and so it was in there with fluid for 18 years. It may, in other words, need to be rebuilt. However, in the interests of "wanting to know", I've installed it and I will determine how it is on a road test. Meanwhile, my esteemed US colleague in Le Club 404, Todd Langton, has a 3.5 year old rebuilt unit ready in case I need it....I'm quite sure I will buy it.....
So the engine compartment looks like this (except there's a battery and the wiper motor is installed!), so it's pretty much time to reinstall the hood.
The remaining work:
1. get the new lower rad hose as well as the new 75°C I ordered from Germany in mid-April. I have a very good used lower hose and several old thermostats but I'd rather put a new one in
2. all the fluids (gearbox, injection pump sump oil, brake fluid, coolant, engine oil, windshield washer fluid, ~20L of 94 octane no ethanol gas)
3. verification of valve clearances (engine builder did it but I'll "trust, but verify")
4. use the factory fuel injection tool kit to check the 5 main settings of the throttle body, etc.
5. buy a new battery, check the electrics
6. spin her up with plugs out to spread the oil around
7. then try to start.
![Immagine](https://i.ibb.co/GCbR1D3/Engine-with-braking-system-in.jpg)