Focus Mk2 1.6 Won't Start but cranks - fuel is getting to the injectors!

[TomsFocus]

Common rails run ridiculously high fuel pressure, a filter post HP pump would cause too much of a restriction.  Plus it would just rip through a paper filter like it was Tesco value bog roll.  

 

[Antonycc]

37 minutes ago, nicam49 said:

You are meant to observe meticulous cleanliness. The main filter is 3 microns, yes, that fine ... almost virus size! Cap everything off when you disconnect it, ideally don't reuse the old pipes! (I know, I know) I always wrap clingfilm over the open ends of any pipes I've disconnected even if only for a short while, also I've bought a Ford kit of assorted caps for sealing off pump, pipes, injectors. 

Hmmm, I see.

[Antonycc]

23 minutes ago, TomsFocus said:

Common rails run ridiculously high fuel pressure, a filter post HP pump would cause too much of a restriction.  Plus it would just rip through a paper filter like it was Tesco value bog roll.  

 

Ha, good point!

[Tdci-Peter]

11 hours ago, Antonycc said:

why isn't there a filter post pump?

A filter after the HP pump would have to be immensely strong, built of 25mm thick solid steel or something. So it would be big, heavy, expensive and very difficult to change. Pump failure is quite rare (though the Delphi system on the Mk1 Focus did go through a bad patch quite a few years ago), so it would not really be worth it. Putting some non-user serviceable fine gauze inside the common rail somewhere might be an option I suppose, though there is a risk of it causing more problems than it cures overall.

[Antonycc]

7 minutes ago, Tdci-Peter said:

A filter after the HP pump would have to be immensely strong, built of 25mm thick solid steel or something. So it would be big, heavy, expensive and very difficult to change. Pump failure is quite rare (though the Delphi system on the Mk1 Focus did go through a bad patch quite a few years ago), so it would not really be worth it. Putting some non-user serviceable fine gauze inside the common rail somewhere might be an option I suppose, though there is a risk of it causing more problems than it cures overall.

Understood.

Well, I still don't know what's wrong yet. There is an obvious leak it seems. I'm lead to believe that pressure shouldn't drop to nothing a second after I stop cranking. The thing is, I can't see any leak and everything is very tight. 

I've done the DPF reset and the DTC has gone now.

I've got 4 injectors on their way. I have a test to do too. I want to get 3 or 4 bolts and screw them into the injector nuts. Crank and see if it can maintain pressure. If it can maintain pressure, then one or more of the injectors are stuck, broken or whatever. Then I'll connect each injector one by one and test each time. I'm hoping to find a leaky injector.

[Tdci-Peter]

On 5/21/2020 at 11:43 AM, Antonycc said:

Ha, good point!

There is good reason for the extreme pressure. Common rail diesels are more powerful (for a given capacity), more efficient, and have lower emissions than the older DI or Indirect types. The high pressure makes it possible to use a very tiny, fast acting, electronically driven solenoid or Piezo valve, which in turn makes multiple injection pulses per firing cycle possible. This controls peak temperature, and controls the rate of pressure build up in the combustion chamber. High pressure and a smaller nozzle create smaller oil droplets, which burn faster & cleaner than the bigger droplets of older engines.

A quieter, smoother drive, less damage to the wallet, and less damage to the rest of the planet is the result if all goes well. Sadly, sometimes all does not go so well!

[Antonycc]

Ok, I now have around 350bar and it doesn't lose pressure straight away.

It's still not starting, but I've not put the plastic air intake thing back on the engine. I don't know if that makes any difference.

[nicam49]

 

350bar?what have you done to achieve it.. you should be seeing pulses at the injectors now. 

[Antonycc]

3 hours ago, nicam49 said:

 

350bar?what have you done to achieve it.. you should be seeing pulses at the injectors now. 

I replaced the injectors with some other old ones. Maybe one of them was stuck or something.

There are still no pulses on the multimeter. Do I need a logic analyser instead?

There's still loads of plastic crap not attached.

[nicam49]

I've got a set of node lights which illuminate to show the presence of injector pulses. They're really low tech! Just normal filament bulbs in a suitable holder that light dimly in time with the pulses. btw, what colour is your cam sensor? with my Mondeo TDCi there was an issue with ones of a certain colour... black ones are suspect, grey ones are good. . 🤔

[TomsFocus]

How long have you tried turning it over for?  The HP system needs to bleed through now, can take several seconds of cranking or even a tow start to get them going after a filter change, let alone a full injector change.

[nicam49]

 Jump start? If it's chain driven timing, then certainly jump start isn't recommended (going on mondeo mk3s here) as chain is known  to jumping. due to snatching on the  tensioner. If you find the battery is being drained too quickly, pull the large (maybe 60amp) fuse that feeds the glowplugs. 

[Antonycc]

3 hours ago, nicam49 said:

I've got a set of node lights which illuminate to show the presence of injector pulses. They're really low tech! Just normal filament bulbs in a suitable holder that light dimly in time with the pulses. btw, what colour is your cam sensor? with my Mondeo TDCi there was an issue with ones of a certain colour... black ones are suspect, grey ones are good. . 🤔

Mine is grey, I accidentally snapped it off a few days ago. It's in but loose.

[Antonycc]

2 hours ago, TomsFocus said:

How long have you tried turning it over for?  The HP system needs to bleed through now, can take several seconds of cranking or even a tow start to get them going after a filter change, let alone a full injector change.

10 seconds or so.Forscan says its 350bar, so surely that should be enough pressure?

[Antonycc]

13 minutes ago, nicam49 said:

 Jump start? If it's chain driven timing, then certainly jump start isn't recommended (going on mondeo mk3s here) as chain is known  to jumping. due to snatching on the  tensioner. If you find the battery is being drained too quickly, pull the large (maybe 60amp) fuse that feeds the glowplugs. 

It's not chain driven. Thanks, I'll try that. First thing though, I need the injectors to fire!

[Antonycc]

This part hasn't been put back on, so 8 holes are showing. Would it start without it?

[Antonycc]

It currently looks like this. Should it b able to run like this?

[TomsFocus]

17 minutes ago, Antonycc said:

It currently looks like this. Should it b able to run like this?

Just give up and buy another car tbh.   

You mentioned the cam sensor was loose above, it needs to be in exactly the right place and properly tight.  

I doubt it's gonna run like that tbh, you're missing MAP & MAF inputs, EGR is open, and if it does start there's gonna be oil everywhere from that cam cover lol.  Those 8 holes are the intake ports, don't drop anything in there FFS!  

If you pull the fault codes now, that should tell you which parts it actually 'needs' but personally I'd refit the pipes, covers and intake mani before trying.

[Antonycc]

7 minutes ago, TomsFocus said:

Just give up and buy another car tbh.   

You mentioned the cam sensor was loose above, it needs to be in exactly the right place and properly tight.  

I doubt it's gonna run like that tbh, you're missing MAP & MAF inputs, EGR is open, and if it does start there's gonna be oil everywhere from that cam cover lol.  Those 8 holes are the intake ports, don't drop anything in there FFS!  

If you pull the fault codes now, that should tell you which parts it actually 'needs' but personally I'd refit the pipes, covers and intake mani before trying.

Ok, I'll refit it all later on. It will only take 15 mins or so.

I just want to get the bare minimum setup to see if it actually works, instead of constantly stipping it off, putting it back on, etc.

[TomsFocus]

3 minutes ago, Antonycc said:

Ok, I'll refit it all later on. It will only take 15 mins or so.

I just want to get the bare minimum setup to see if it actually works, instead of constantly stipping it off, putting it back on, etc.

Yeah, I understand why you left it, just think there's too much left off at the minute for it to be a fair test.  You could've done that with older cars but it's all so complex and reliant on sensors nowadays.

Once it's back together, pull the fault codes, make a note of them, then clear them.  Then making sure the battery is fully charged, switch the ignition on to get some heat in the plugs, then give it a good burst of cranking for ~20 seconds or so.  Spray some brake cleaner or easy start in if it still doesn't catch and try again.  If it's still not having it, check for fault codes again.

The 350bar is easily enough pressure to start, so if it still doesn't go now, there's another issue.

[Antonycc]

3 hours ago, TomsFocus said:

Yeah, I understand why you left it, just think there's too much left off at the minute for it to be a fair test.  You could've done that with older cars but it's all so complex and reliant on sensors nowadays.

Once it's back together, pull the fault codes, make a note of them, then clear them.  Then making sure the battery is fully charged, switch the ignition on to get some heat in the plugs, then give it a good burst of cranking for ~20 seconds or so.  Spray some brake cleaner or easy start in if it still doesn't catch and try again.  If it's still not having it, check for fault codes again.

The 350bar is easily enough pressure to start, so if it still doesn't go now, there's another issue.

Fanx, will do.

[Antonycc]

Ok, so I out all the crap back on the engine. There were vibrations, it was trying to start. I kept cranking, the a break, and again and again and it did start for about 2-3 seconds at one point, but I stopped cranking and it turned off.

It's not started since and it doesn't seem to be trying anymore. It cranks but there are no vibrations. 

I forgot to squirt out the fuel from the high pressure pipes though before connecting to the new injectors. Oooops!

[TomsFocus]

Common rail injectors bleed themselves, there's no need to bleed the HP pipes if that's what you mean.  You just need to prime the filter with a hand pump but I think you've already done that?  It wouldn't hurt to prime it again though, or at least check it's still full of fuel.  These engines don't use a lift pump in the tank like some others, they absolutely rely on your hand priming to fill the filter with fuel first.

If you manage to get it started for a few seconds again, mash the throttle to keep it going!   

How's the cam sensor btw?  Is that tight now?

[nicam49]

OK, so the injectors are being triggered now at least. Are the leak-off pipes fully connected.... O rings looking good? I've had air in the fuel pipes due to a poorly sealed  leakoff pipe. It recycles via the fuel filter, causes havoc. Had to be towed home. 

[Antonycc]

18 hours ago, TomsFocus said:

Common rail injectors bleed themselves, there's no need to bleed the HP pipes if that's what you mean.  You just need to prime the filter with a hand pump but I think you've already done that?  It wouldn't hurt to prime it again though, or at least check it's still full of fuel.  These engines don't use a lift pump in the tank like some others, they absolutely rely on your hand priming to fill the filter with fuel first.

If you manage to get it started for a few seconds again, mash the throttle to keep it going!   

How's the cam sensor btw?  Is that tight now?

I superglued the cam sensor. it's fine now.