Injectors misbehaving but trying to understand the numbers

[MattBLancs]

Assume about 2 weeks in my experience for Autodoc stuff to roll up

[darbuck]

Ok thanks Matt and Steve

[darbuck]

Just a quick question lads does anyone know what pressure Delphi injectors pop off at. Just for reference I am testing mine with a pop tester and Chinese electronic controller. I have four that pop off around 2800 psi one of them is around 2600 and I have four that don't seem to pop off at any pressure and leak off continuously. I also have one that pops off about 1500 psi. Which indicates it is worn. I am trying to figure out what is good and what isn't. I am still waiting on gaskets for Dpf and turbo. I want to completely rule out injectors.

[MattBLancs]

Do common rail injectors have a "pop pressure"?

Old injection pump type diesel injectors had a specific pop pressure at which they kept closed until popping open so as to try and give a clean start and stop to the injection cycle (I e. No dribbling or dripping) where as a common rail injector is opened like a solenoid, and sees a near constant pressure upstream.

Not certain either way, but can't understand why it would need a specific pop pressure if opened and closed on demand as a solenoid??

[darbuck]

Not sure either,They still have opening pressure for the needle to lift by my understanding just at different pressures. They work similarly to old fashioned injectors they just have the electronics to aid flow rate management at different speeds which is where they differ to the mechanically timed pump if you get me?

I need to do more research on them. Mine are piezo rather than solenoid so I don't think they are the same. I'll let you know when I know more.

[darbuck]

I'm not sure what colour cerine or its products are but the orange colour is probably from the iron which is also part of the Eolys formula.

Hi Paul was that your video on the Peugeot 508 turbo intake on YouTube 4 years ago.If so did you ever figure out why it was doing that.

[Paul-R]

No, not me. I've never had a 508 or posted a YouTube video!

[darbuck]

Ok thanks Paul. Someone else so.

[darbuck]

Hi lads, do any of you have any suggestions for testing the pre-cat off the car for flow, at this point I am unconcerned with efficiency just flow. I have cleaned mine but I think it is a bit restricted and I think it was a combination of it and the DPF causing the turbo to blow its seals. Any input would be appreciated.

[darbuck]

Ok so I pulled out the smoke machine again and ran it through the cat all good. Just as another attempt of determining if it had a blockage I blew through it I couldn't feel any resistance so I am assuming it is ok so panic over. I just don't want to have to take it apart again. I'm going to start reassembly today hopefully. I was sick all week so kind of put a spanner in the works.

[Rhothgar]

Yes, exactly - doesn't even burn well!

Let them dry out for 6 months and then see what you think!

The brown needles go up like they’ve had petrol poured on them.

[darbuck]

Yeah I know I will torch them in the new year

[MattBLancs]

Ok so I pulled out the smoke machine again and ran it through the cat all good. Just as another attempt of determining if it had a blockage I blew through it I couldn't feel any resistance so I am assuming it is ok so panic over.

.

Assuming you meant blowing through it err, "manually" I don't think you can get much flow - certainly a couple of lung fulls is next to nowt compared to a running engine - so it'd have to be pretty horrendously clogged before you'd feel much blowing into it.

I've no direct experience, but have read of catalysts collapsing and therefore blocking, so if looks ok I'd probably call it right. No experience with the smoke machine but sounds handy and nothing lost giving it a try.

I'm going to start reassembly today hopefully. I was sick all week so kind of put a spanner in the works.

Get well soon, hope you get some good weather so you can make progress.

[MattBLancs]

Spot of maths!

https://www.bbc.co.uk/bitesize/guides/z ... (500%20ml).
Tells me "0.5 litres per breath"

2.0 engine x 0.5 (four stroke, hence 2 revolutions required for cycle) x 1000 rpm = 1000 litres per minute = 16.7 litres per second.
16.7/0.5 = 33.3

I.e. a 2.0 virtually idling, "breathes out" the same volume we do, 33 times per second!

The flow of air in and out of a running engine is quite remarkable when you think about it!

[darbuck]

Thanks for that yes so I could actually feel my breath coming from the other side so mustn't be too bad.

I had posted a minute ago what ever happened I don't know. Thanks Matt. I'm on the mend thankfully.

Turbo is in apart from the pipe work I'll take a pic of it in situ if the rain lets me.dodging the rain all day,

Yeah engines are really good air pumps when you think on it. They move serious quantities of gas in their lifetime.