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

[Tdci-Peter]

37 minutes ago, Antonycc said:

f I was to trick the ECU into thinking that pressure was 200bar (by using a voltage divider on the FRP sensor), would the ECU then power the injectors? (As a test ofcourse).

Also, another question on a different matter; Forscan says that a dpf regen can only be performed when the engine is 65c. Which sensor is it referring to?

It would take some judicious juggling of resistors to get a 200Bar signal. I have not looked at the calibration of the sensor, but I guess that 5v at the signal would be between 1600Bar and 2000Bar. So an extra 100Bar is about an extra 0.3v at the signal. It would test if the low pressure signal is the only thing that is stopping it firing, or if there is something else.

On the tow start, I was thinking that you could get say 1000rpm constant-ish, compared to only 200rpm or so when on the starter motor. Again just to test if the pressure goes up.

The engine temperature signal can only be the cylinder head sensor (CHT), there is no other suitable one. Intake air temp & fuel temp are the other engine related sensors, but do not seem right for enabling DPF regens. However any error that raises an engine DTC is also likely to prevent regens.

 

 

[Antonycc]

On 5/15/2020 at 10:50 PM, nicam49 said:

Hi, check that your new pump is giving enough pressure:

 disconnect all the electrical drives to the injectors and also disconnect the electrical connection to IMV. This causes the IMV to be fully open. If you now crank the engine you should see >1050bar

I get 4.5bar.

[Antonycc]

OK, with everything reconnected, I can get around 100bar, but it loses pressure almost immediately after I start cranking.

[Antonycc]

Ok, I get around 1ml leakoff for 30 sec of cranking.

[Antonycc]

With the return pipes off, when i squeeze the priming bulb, fuel pisses out of the return pipes.

[Antonycc]

[Antonycc]

I've tightened the fuel rail pressure sensor and I've got a little more pressure.

[Antonycc]

The story continues...

[TomsFocus]

Have you actually got a DPF?  I'm still confused as to whether it was gutted but not mapped?  If so, that's just asking for trouble lol.

[nicam49]

2 hours ago, Antonycc said:

I get 4.5bar.

Hang about! So, with all injectors electrically unplugged and the IMV (on the rear of the pump) also unplugged, and you crank if for 30 secs max whilst live monitoring the frp, you're only getting 4.5bar?       And that's on the 2nd hand (new to you) pump. But you get 100 bar when cranking normally. Then you've either got a knackered pump or one or more injector is jammed open and leaching all the pressure. 

[Tdci-Peter]

8 hours ago, Antonycc said:

I get 4.5bar.

From my Forscan picture earlier, it looks like the IMV needs to be energised to raise pressure. It makes sense as over-pressure is damaging and maybe even dangerous, so off should be low pressure. The VCV signal is the drive to the IMV, it is high when cranking starts, dropping back as the pressure rises. So 4.5 Bar would be expected if your 1.6 is the same as my 1.8.

8 hours ago, Antonycc said:

With the return pipes off, when i squeeze the priming bulb, fuel pisses out of the return pipes.

A return pipe comes from the pump. When the IMV is open (de-energised), all the fuel from the rather feeble 1st stage of the pump is dumped into the return system. As the IMV closes, progressively more fuel is pushed into the very powerful 2nd stage, and on to the rail & engine. A priming pump can push fuel through the 1st stage into the return system. The rather feeble and leaky nature of this part of the pump is one reason why these pumps will not suck air, they have to be primed with fuel to work.

1ml of fuel in 30sec does not sound much. Not what I would call a giant leak. Was that all 4 injectors, and what about the return pipe from the pump? Unless it is leaking somewhere else, like into the cylinders. A damaged injector nozzle could cause that.

If the rapid drop in pressure on your graph happened as soon as you stopped cranking, it may point to a leaking injector. I am sure my engine retains far more pressure than that on switch off.

I have seen that DPF DTC up lots of times, but not heard of it preventing the engine from starting. It usually just causes a reduced power mode, or puts the warning light on.

[nicam49]

Interesting... It's a Bosch system, is it? I know that the test I recommended to test the pump pressure , ie disconnecting the IMV and injectors, works on the Delphi system... perhaps the Bosch IMV works the opposite way round. 

[Antonycc]

18 hours ago, TomsFocus said:

Have you actually got a DPF?  I'm still confused as to whether it was gutted but not mapped?  If so, that's just asking for trouble lol.

Why is it asking for trouble? lol

[Antonycc]

18 hours ago, nicam49 said:

Hang about! So, with all injectors electrically unplugged and the IMV (on the rear of the pump) also unplugged, and you crank if for 30 secs max whilst live monitoring the frp, you're only getting 4.5bar?       And that's on the 2nd hand (new to you) pump. But you get 100 bar when cranking normally. Then you've either got a knackered pump or one or more injector is jammed open and leaching all the pressure. 

Correct. All unplugged, IMV unplugged and the new one is 4.5bar.

The old pump was 4.5bar whether cranking or not.

The new pump is 4.5bar as you said, or 100bar when all electrics connected.

[TomsFocus]

1 minute ago, Antonycc said:

Why is it asking for trouble? lol

I think you've found out why...  

The ECU will keep trying to regen the DPF if it thinks it's still there.  It'll fail every time (hopefully...otherwise you're risking a cracked block or even an engine bay fire) and eventually you'll get stuck with the regen duration fault code and permanent limp mode.  Not to mention your oil will be considerably thinned with diesel and not lubricating as it should.

 

They do generally still start though, so I'm not 100% sure that's your only issue - but it is definitely one issue.  If you're not going to get it mapped, I'd suggest you reset the DPF learned values so the PCM at least thinks you've got a new DPF.  But it is far from an ideal situation! 

[Antonycc]

12 hours ago, Tdci-Peter said:

The rather feeble and leaky nature of this part of the pump is one reason why these pumps will not suck air, they have to be primed with fuel to work.

They do? How? I never primed the pump as such, I just connected it then squeezed fuel into it via the bulb. I thought that's all I had to do.

12 hours ago, Tdci-Peter said:

1ml of fuel in 30sec does not sound much. Not what I would call a giant leak. Was that all 4 injectors, and what about the return pipe from the pump? Unless it is leaking somewhere else, like into the cylinders. A damaged injector nozzle could cause that.

It was approx 1ml per injector. I didn't notice anything come out of the return pipes, but then I didn't really look.

12 hours ago, Tdci-Peter said:

A damaged injector nozzle could cause that.

Ok ok... So I'll look at that. Is there any way to test? Thanks so much for your help by the way - I really do appreciate it. 

[Antonycc]

3 hours ago, nicam49 said:

Interesting... It's a Bosch system, is it? I know that the test I recommended to test the pump pressure , ie disconnecting the IMV and injectors, works on the Delphi system... perhaps the Bosch IMV works the opposite way round. 

It's Bosch 937 I think.

[Antonycc]

2 minutes ago, TomsFocus said:

I think you've found out why...  

The ECU will keep trying to regen the DPF if it thinks it's still there.  It'll fail every time (hopefully...otherwise you're risking a cracked block or even an engine bay fire) and eventually you'll get stuck with the regen duration fault code and permanent limp mode.  Not to mention your oil will be considerably thinned with diesel and not lubricating as it should.

 

They do generally still start though, so I'm not 100% sure that's your only issue - but it is definitely one issue.  If you're not going to get it mapped, I'd suggest you reset the DPF learned values so the PCM at least thinks you've got a new DPF.  But it is far from an ideal situation! 

I'm stuck with a code now. "Maximum number of regeneration demands reached." Whatever the hell that means.

[nicam49]

So, with original pump you were getting 100 bar, and with s/h 'new' pump, something similar.  When I had a low pressure pump fault, the course of action was cheapest 1st (fuel filter), followed by slightly more expensive items (frp sensor, IMV) then finally pump. Of course, on a 02 plate car with >200kmiles on the clock, it was always going to be the pump. But yours failed catastrophically while driving, and now you're reading  low fuel pressure. I take it the s/h pump came with its own IMV,?  When I bought a frp sensor, it came c/w common rail and all injector pipes and I saw a YouTube vid where someone had fabricated a common rail blanking plug by silversoldering up the end of one of those injector pipes, so they could use it to eliminate a faulty injector by taking it off the common rail and blocking the injector port. (get my meaning?) Seeing as you must be quite handy (you did replace your pump) perhaps this is a course of action to take. The above is just me thinking aloud, btw. 

[TomsFocus]

1 hour ago, Antonycc said:

I'm stuck with a code now. "Maximum number of regeneration demands reached." Whatever the hell that means.

It's failed too many regens so will be in limp mode even if it does start as I said above.  

You need to run the service procedure to reset the DPF learned values so the ECU thinks you have a new/clean DPF.

 

[Antonycc]

6 hours ago, nicam49 said:

So, with original pump you were getting 100 bar, and with s/h 'new' pump, something similar.  When I had a low pressure pump fault, the course of action was cheapest 1st (fuel filter), followed by slightly more expensive items (frp sensor, IMV) then finally pump. Of course, on a 02 plate car with >200kmiles on the clock, it was always going to be the pump. But yours failed catastrophically while driving, and now you're reading  low fuel pressure. I take it the s/h pump came with its own IMV,?  When I bought a frp sensor, it came c/w common rail and all injector pipes and I saw a YouTube vid where someone had fabricated a common rail blanking plug by silversoldering up the end of one of those injector pipes, so they could use it to eliminate a faulty injector by taking it off the common rail and blocking the injector port. (get my meaning?) Seeing as you must be quite handy (you did replace your pump) perhaps this is a course of action to take. The above is just me thinking aloud, btw. 

Original pump 4.5bar.

New pump 100bar.

Both IMVs say the same.

Good idea... I guess i Could do one better than that. Just get a bolt and a piece of rubber and put the both into the high pressure injector nut thing.

[Antonycc]

6 hours ago, TomsFocus said:

It's failed too many regens so will be in limp mode even if it does start as I said above.  

You need to run the service procedure to reset the DPF learned values so the ECU thinks you have a new/clean DPF.

 

Yes... About a week or so before this was happening, it kept cutting out at 200rpm.

Ok, I'll try that..

[Tdci-Peter]

10 hours ago, Antonycc said:

I just connected it then squeezed fuel into it via the bulb.

Yeah, that is all I mean by priming. Once much air gets into the line from filter to pump, you have to push fuel through with a bulb to get enough of the air out, so it will work.

I know a bit about pumps & valves & stuff, it is part of my job, but not specifically about the 1.6TDCI except what I have picked up on this site. All these common rail systems are very similar in principle, but there will be detail differences, like which way round the IMV works, as Nick suggested. I have the Seimens/VDO system, the 1.6 has Bosch, the Mk1 Focus 1.8 had Delphi.

Take care with the high pressure pipework, 1500Bar is 22,000PSI, a very, very high pressure. Rubber is about a strong as water at that sort of pressure. All the seals will be metal to metal in the HP system.

It does start to sound like your engine had a major pump failure, and the debris from this failure can easily damage injectors. They are very sensitive to any dirt, swarf etc.

 

 

[Antonycc]

11 hours ago, Tdci-Peter said:

Yeah, that is all I mean by priming. Once much air gets into the line from filter to pump, you have to push fuel through with a bulb to get enough of the air out, so it will work.

I know a bit about pumps & valves & stuff, it is part of my job, but not specifically about the 1.6TDCI except what I have picked up on this site. All these common rail systems are very similar in principle, but there will be detail differences, like which way round the IMV works, as Nick suggested. I have the Seimens/VDO system, the 1.6 has Bosch, the Mk1 Focus 1.8 had Delphi.

Take care with the high pressure pipework, 1500Bar is 22,000PSI, a very, very high pressure. Rubber is about a strong as water at that sort of pressure. All the seals will be metal to metal in the HP system.

It does start to sound like your engine had a major pump failure, and the debris from this failure can easily damage injectors. They are very sensitive to any dirt, swarf etc.

 

 

I have some injectors coming. If this is the case, why isn't there a filter post pump?

Antony

[nicam49]

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.