Diesel not starting after replacing injectors
 

Right guys following on from the last couple of days with removing the injectors on my diesel zt, i have now refitted my replacement injectors however the now won't start. I have plenty of fuel pressure coming from the low pressure pumps, ive cracked open the fuel lines to the injectors slightly and there is fuel there, ive done a leakback test whilst cranking the engine and there is very little leakback even after cranking several times at around 5-6 seconds a time. The rev counter is moving whilst cranking. Ive tried easy start and even that isnt starting the car, just turns over a bit better. Amy ideas? Could there be air in the system preventing it from starting? Cheers

You say there is little leakback, you should have none if they are refurbed.

Silly question but you have connected up all the electrical bits when you’ve put the manifold back on, the connector under the left hand side sometimes gets missed (yes usually by me!)

They're not refurbed, just replacement second hand ones. I've had refurbed before, thats what i've just taken out. Only lasted 3 years and refurbed injector2 was leaking back like mental, filled up my leakback bottle in about 15 seconds of running the engine.

Ive plugged all the sensors in including the cam sensor as i had to replace the rocker cover due to a hole in my old one which was leaking oil.

Ive still got my leakback test kit on the injectors and can see quite a few air bubbles coming through still as i'm trying to crank it, especially on injectors 2 and 4.

even my old pile fired up on easy start with the itp dead .and the u/b pump just about working.

Think it may be a matter of keep trying until all the air gets out. Still seeing a lot of air bubbles coming through my leakback test pipes.

Hi Rick,
You have probably done this but....Check to make sure the fuel rail pressure sensor is fully home mate, I presume these injector or injectors came from a reliable source
Mick

Make sure the injectors are bolted in correctly and have a perfect seal... although i assume you'll have done this.

I'd take it apart and put it back together again, they have running fuel pumps so air shouldnt be too much of an issue.
you only really need to bleed injectors on old VE style engines with vaccum radial pumps like my old A4 TDi

Fuel rail sensor is all the way in cheers mate. That sensor hasnt been touched whilst working on the car either.

Ive checked that the injectors are all the way in. Just to make sure i undone the whole lot pulled the injectors out and refit just to be sure. Gently tapped the injectors down until i could tell they were in fully. All new copper rings on the injectors too.

Just taken these readings below whilst cranking and fuel pressure seems fine in all areas?

CheersAttachment 73695

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Looks fine on the screen yeah mate... thats a confusing one, the one thats getting me is that it wont run even on easy start... that should cause it to fire even without fuel... its why i was asking if the injectors are sealed correctly as i remember cleaning my nozzles i accidently fitted the retaining brackets the wrong way round so the injectors just moved up and down when cranking and it wouldnt start.
Realised swapped them back over and it fired first turn pretty much. :duh::duh:

The injectors are down as far as they can go and the clamps are in the right way ;) i have made that mistake before.

The only other thing ive changed is the rocker cover as mine had a split in it. Now to remove the rocker cover you have to unbolt the injector clamp threads, when refitting the replacement cover i've done up the threads as much as they will go with medium power without doing them up too tight as they seem like they could easily snap. The threads have like a rubber ring at the bottom so ive tighed them up to the point where they grip the rubber but not any tighter. Is this how much i should tighten the threads for the clamps, or should they be tightened to the point they squeeze the rubber washers?